The Twin Screw Thread
 

With Andy phasing out of the TS world and many of us having his systems there are a lot of questions and ideas that I think arent going anywhere. Maybe this can be a thread where we can do some Q & A and maybe improve on what we have. Maybe even swap some parts.

For instance, somehow the fact that the pre S4 radiator hose (ds) remedies the cut hose problem didn't get passed along to all.

Critiquing the system is fair game also, especially if there is a solution by the critquer :burnout:

928 SP SC link
https://rennlist.com/forums/928-forum/230957-sneak-peek-supercharged-by-928-specialists.html

Customized Supermodel set up.
https://rennlist.com/forums/928-forum/242306-sc-install-with-links-to-pics.html

Also, if you have the snout support with the 3 aluminum cyclindrical spacers on the back...CHECK them. One of the spacers on Darriens "kit" was a different length. If it was supposed to be that way, i havent seen anything to show me that?
It skewd the whole alignment of the tensioner/ilder pulley and messed it up. Scuffed up a SC belt as well when the car was first started and the belt found its comfortable running position.....half of it folded up on to the AC pulley! :banghead:

By adding a couple of thin washers to the spacer i got Darriens belt running smack dab in the middle of the idler pulley.

Ive got a few things relating to the I/C system that cleans it up a bit. The newer manifolds have the I/C inlet pipe on the top. The older ones were in the front and allowed for a more stealthy run of hose to the heat exchanger.
I fab'd up a 180' turn for Darriens so the hose can now run under the snout and down along the lower rad hose where it eventually meets the heat exchanger inthe front bumper.
this was the copper fitting i made
http://members.rennlist.com/v1uhoh/Ic180fitting.JPG


Ill get a pic of it at some point. Its not really needed, but we didnt care for a big 3/4" hose coming off the top of the manifold towards the passenger fender area.

Also, something im looking into eventually is some more boost. With a swap to a smaller pulley i think you will run up against some significant belt slip as we dont have the nice belt wrap like DR has on his setup :bowdown:
Another way to increase the boost besides going to a smaller upper pulley is to make the lower pulley bigger :evilgrin:
I havent tried it yet or done the math on the pulley ratio/boost etc. but believe it or not, the MURPH lower pulley may be useable on the TS set ups. Even though Murph uses 8 rib and the TS 6rib, the plane that they run in is the next position fwd of the AC pulley. This would give you a larger LOWER pulley instead of a smaller upper......as not to get to wild you would probably have to go to a slightly bigger upper pulley also(hood clearnce???..dunno)! Just a thought for you Jim....since 460 HP isnt enough :evilgrin:


top...stock
middle...TS
bottom ...MURPH

Jim,
I think this is a great idea! As well there are people out there that are about to install their SC who need Tech help.
My car was running open loop, not using a CO sensor. If anyone needs help in that area let me know.
I like the look of Bills throttle cable setup. Any chance of getting more info on that?
Heres a picture of my fresh air intake. Easy to do.

BINGO.
Details on that Daryl. We are looking for some solution on Darriens 86.5..what did you have to move to do that.
Coil....jumpstart terminal?

Pics please...inside the fender as well. I like it.


Good idea ya posted here Jim :cheers:

We are using Bills set up on Darriens car also. Gives a nice clean approach for the cable to the throttle linkage on the TB.

Ill grab pics next time i go up there.

Could this be done on the Supermodel forum, or is it defunct?

Sad to say but.... I am almost relieved that my car went up in smoke. Now I am free of the whole cobbled together mess and can start fresh with a more user friendly system that has some REAL customer support!!

I miss my car, I miss running a 928 with boost but not much else....

A bigger lower pulley... I like it. What boost do you run consistently Tony and do you have to tighten your belt a lot to keep your boost up.

IMHO...From what i can gather people arent being given the time of day on that forum from the person that should be giving it.
So, why give the forum the traffic and the owner the return favor.

There is a great wealth of knowledge and diversity on THIS forum alone that can be of benefit to the folks out there who run the twinscrew. The people who provide it dont have access to the "supermodel" forum and most likely arent TS owners, so if they want to chime in on this thread they are more than welcome to and dont have to be "approved" to do so..

I imagine over time the thread here will fall off the pages or perhaps turn into a TS vs CS vs TURBO debate but in the mean time it seems like a pretty good idea?

No doubt there are better ways to end the Supermodel system than the way Andy has. I think he is just burned out. Are you selling the TS?

I am. Or already have as soon as I can get it off the car and shipped to Warren. He has a partial from Andy, so maybe with what is usable from mine and what he has already got, he can put together a useable system.

i seem to run appx 7-8lbs on most of the logs i have looked over. I havent tightened my belt in a while and im sure it could use it, but i need a shorter belt really. I have placed marks on the belt and the SC pulley and it does slip now and then.
:cheers:

At sharktoberfest Bill and Derek, mentioned that the inlet and relief on the BEGI was backwards causing full rich conditions which I had any time I ran 30# injectors. Does anyone have a diagram on how it is supposed to be? Might help future installers from going down the same road.

Tony are you going to try for 10 or 11? I'd really like to see the power curve on that. It would be great to compare that to whomever else has gone that high. Do you have enough fuel for that?

Has anyone taken over from the Supermodel kits? Are the 928 Specialists kits the continuation of what was being done? They sure look similar. Do they have the same intercooler manifold setup? How close are they or are they the same thing, or am I totally out in left field here?

EB,

You are correct as far as the manifold and IC but I think that is close to where the similarities end.

Well, a new Walbro 255lph pump is enroute, that will help.
30 or 42lbs injectors will have to go in...probably 30s as the 42s wont idle too well from what ive heard.

as far as the BEGI unit SHANE, ill get a pic. Im wating as i type for an overhaul kit from them as i bew up the metal diaphram in mine with a fuel pressure experimentgone bad LOL. I wanted to data log the differnt fuel pressures and slope vs boost as i adjusted the needle valve and center screw. The over haul kit i think includes a schematic of the device...ill no more when it comes. Ill grab a picture of mine when i get it set back up.
The check valve goes on the needle valve fitting...NOT THE BARBED FITTING ON THE OTHER SIDE.

If you mean the fuel lines, the BEGI unit should have been stamped with the letters "IN" above one of the 1/4npt ports.

Also if you have a ruptured diaphram, your fuel pressure will pretty much max out and the car will run rich untill it dies....thats what mine seemed to do.
Your pump will also make wierd noises...i think it was cavitation on mine.
each failure may manifest itself differntly....but thats what happend to me a few days ago.
HTH

I was under the impression that the 928SP kit was indeed the next evoloution of Andy's kit, and that he was helping them with the development. He was going to do it with Devek, but I guess that fell through. Andy's a smart guy, and you have to give him credit for getting the system off the ground. He just could not keep up with the constant demand for tech support. It makes perfect sense for him to try to pass off the kit to one of the "Big 3" to take over sales and support.

EB338, look for the original 928 Specialists supercharger thread. The similarities and differences were discussed. IIRC, none of the major components are compatible.

Without a doubt

It absolutely makes sense for him to pass off the kit... however, there are a lot of people with his 'old' kits who are still waiting for parts, can't get answers to installation problems etc. that are feeling pretty screwed. A few quick e mails from Andy would go a long way for some folks.

Here ya go

928 SP SC link
https://rennlist.com/forums/showthread.php?t=230957

Customized Supermodel set up.
https://rennlist.com/forums/showthread.php?t=242306

Shane I am pretty sure we got the BEGI 100% correct after the initial head-scratching.

Yep that was how mine was set up. But IIRC, they were suggesting it be the other way around. My needle valve was wide open and the adjusting screw was just barely turned in, and I still had to have an aditional needle valve on the vacuum/boost line going to the BEGI to limit the signal it was seeing. Otherwise I was still way rich even with the 24# injectors.

I actually don't think Andy was aware of the hose fix right away. By the time he knew of it and verified it, he was already on his way out of the 'scene'. It also isn't an idiot-proof swap... the hose gets much closer to the fan and CAN be cut by the fan if not installed a certain way.

I haven't had my own supermodel for a while, but IIRC, that "pipe" in front of the SC for the IC is actually an IC OUTPUT (not input). It was designed that way for a reason. If you put water INTO it, there is a chance that water would go in, and run out the bottom of the IC (and not fill the entire IC up thereby reducing efficiency).

The supermodel forum isn't really accepting new users. It currently serves as "knowledgebase" of sorts for customers who already had logins.

I don't think Andy would call it a favor...

Tony: You're a genius! The Murph pulley idea is phenomenal. I like the plumbing change too, although Mike is right - you should fill from the bottom.

Daryl, et al: I will post details on making the throttle bracket soon. I'm still willing to make them for free. Hard to charge for something made with a hack saw and patio door wheels. Here's a link that shows the installation.
http://www.billsworkshop.com/P928S4/sc/throttle.htm

Shane: At Sharktoberfest we never had a consensus on how the Begi should be hooked to vacuum. We had cars running both ways. I don't have one, so I hope you guys sort it out. Regardless, Derek's car was running real rich. Also, he said his AFM was steady and never oscillated as I think they are supposed to. Sounds like a broken 02 sensor, although it had been replaced and Greg Brown spent 5 hours trying to tune it.

Mike: Unless Andy is actively processing the posts on his forum, I don't see how he could be upset with posting here. This is a great place to get more eyes looking at things and it will potentially expand the Eaton/Twin screw fan base. I have always admired Andy and wouldn't want to do anything that would harm or upset him. If this is a real issue, please explain.

You're right, the forum is dead. Regardless of what goes on here or there, I don't think Andy cares either way. I thought he'd ask me to close it down, but he didn't even do that (i wouldn't be surprised if he forgot about it). I only continue to host it so it acts as a knowledgebase for anyone who has a login. I know he's finally busy with his own life once again (now that 928supermodel is "dead"), and i'm happy for him. He's got NOTHING to be upset about, so please do share all the info you can to keep this limited production-run working. All I ask is that people just stop talking about him with ANY negativity... there's no point in villanizing him. Just remember him as someone who tried to give us another option for our cars.

Andy is a stand up guy. This is what I was told and that is what I have come to know. Maybe when (and if) he decides to "chime in" again on a regular basis, we'll have the additional benefit of his insight, but until then, remember he's human. Many of us are better off today because he gave it a shot, regardless how things turned out. It seems to me that if the Supermodel Forum is no longer acting as the knowledge base and discussion center for twin screwers, Tony's idea to use this forum for twin screw threads, Q&A, developments etc. sounds good. Tonys participation makes it even better. Let the games begin.

Daryl:

Can you post some pictures of your cold air intake...I think I like it better than mine.

Regards,

Ken

Glad we got your ok on this :rolleyes:

There are a lot of stand up guys who have given thousands of dollars to Andy. Unfortunately many of them right now are waiting for parts promised long ago or not getting the installation help they were promised before purchase. So I started this thread in the hopes we could help ourselves since the vendor has lost interest.

Jim,
Sorry. I didn't mean to come off in a patronizing manner. I can only speak from my personal dealings with Andy. Although it took him awhile to finalize things with me also, he did.
Your idea of sharing this info still seems like a real good one to me.

Bill I have toi agree, I don't see how what's being said here could be considered bad toward Andy. Personally Andy was VERY helpful to me. I view Andy as a pioneer. Tony took his work to the next level in a serious way, and lest we forget ... Andy always said it was something when we bought from him, that we would have to do a lot of fabbing on. I think Andy did us all a favour. Can't say whether he is a nice guy or not, but he never to my knowledge cheated anyone, and he definitely furthered the 928 development. :cheers:

Mike,

Swapping ideas and fixes and even critiquing the system is all good. :cheers:

As for Andy, he did a great job getting this thing going :cheers: and no one wants to make him into a villain but he still needs to complete the deals he made with many people. I like Andy but it has been very frustrating dealing with him on my second system. Members have blasted a certain vendor recently over shoddy customer service and communication and quite honestly Andy has been every bit as bad.
But, this thread is about the system and hopefully the Andy stuff will die off as he cleans up all of his loose ends.

Actually no he didn't, there was no fab work needed.

And I do believe Andy is a nice guy... and burned out.

:cheers: I think the 'taking awhile' thing gets a lot more stressful when you know that he has moved on with his life.

In a nut shell this is how i gather the BEGI unit works.

the center Hex screw adjusts the fuel presure at 0 manifold pressure ie:NO BOOST and NO VACUUM.

you do this during the set up when you start the car and remove the signal line from the BEGI UNIT....turn the center alan screw until you get the fuel pressure you want at the zero point.... X lbs

When you place that signal line back on the fuel presure will drop as you have removed all the restirctions from the line that the BEGI provides...in Darriens case the fuel pressure should drop to appx 36psi, which is the factory setting on his car with the 24lb injectors....it did, appx 39psi actually.

now, as you transition from vac to boost as your foot goes down :evilgrin: you obviously hit a point of 0 manifold presure in the transition. This is the point where evering things starts to happen. At this ZERO POINT, i like to call it, the BEGI unit will comand a fuel pressure that you set when you took the signal line off during inital set up...Xlbs.

from this point(ZERO POINT) the fuel pressure will rise to a point determined where you set the needle valve. the more closed the needle valve, the higher the resulting fuel pressure you will see.....the more open the valve the lower the fuel press under boost.

I always wondered if the guys running the GTs with the tip in issues had this ZERO POINT fuel pressure set high enough. Obviously if you want to help prevent tip in detonation you want the fueling adequate....there are other factors as well, ignition timing, cams on the GT that mak a difference but the only thing we have control of at this point is the fuel pressure

I got my overhaul kit last night and installed it and my car is back to normal. There was a hair line crack in the metal foil shim. doesnt look like much but it would spike my fuel pressure to over my gauge limit and woudl make the car undriveable. EASY FIX and easy to overhaul the unit. :cheers:

below is a schematic of it with some notes
pics of the foil shim with the crack..
the piston as it protrudes from the bottom of the upper half of the unit. The dark stuff you see is a grease applied at the factory to keep the piston lubricated..over time it perhaps wouldnt be a bad idea to check the foil shim or the lube on the piston.
HTH

Good call Tony. I don't recall us setting the 0 point


Tony said
I always wondered if the guys running the GTs with the tip in issues had this ZERO POINT fuel pressure set high enough.

Ken,
I am attaching four pictures of the cold air intake. They should give you a good idea of what’s involved. Ken if you, or anyone else thinks this will work for them email me at daryllmiller@hotmail.com and I will return email with a parts list, instructions, and complete pictures.

Andy, if you are reading this. THANK YOU for selling me this system. You have helped me renew my interest in the 928. I would be very surprised if you made one cent on this. I am sorry something that you loved and had such a passion for is causing you pain. Sometimes a guy just gets burnt out.

For those out there that need Tech. help installing there system, having problems, or want to share new ideas. That’s what this thread is all about.
Soon I am going to learn how to add one of those happy faces but for now I am having enough trouble just up loading a picture.

It was Jim who started the thread not me...credit where due :thumbup:

Good or bad, what ever i can add i hope it helps. I hope every one else who has ideas, brings them forward as well...good..bad...silly or how ever they deam them.
I thought about that as well, but mine has that little bleed port on the top that allows trapped air to escape....if thats what its used for. Appears to be.? As longs as the pump pushes more water in that can escape and there is a port on the top to get air out, it should fill up.
Everytim i pull that small 1/4" hose off the top, i get water gushing out with the I/C pump running
SO far so good is all i can say if its wrong. :cheers:

I took it one small step, and that was just a few little refinements, more in the appearnce and looks of the set up.
DR is the one who needs the big plug here...hes taken it by the horns and moved by leaps and bounds.

He doesnt appear to care enough to even worry about it.
He can call it what he likes but in my eye he's been pretty disrespectful to many peoples request for help of him or status of parts from him.
' nuff of the Andy chat, he gave us a workable functional supercharger litterally from the workings of a small garage. :thumbup: how he handles him self with his his customers is a bed his reputation has to sleep in.

I still have this pic he sent of the initial fit ment of an Eaton M90...it took alot of time, work, and frustration, thats for sure...he will always get a :thumbup: and respect for what he undertook in my book

Onward........................................................... :burnout:

Tony - that metal shim - is it adjustable how thick it can be, so that if you do need to adjust the top pressures you will not rip it?

Boy, all this would be mute if you guys could get those LH's tuned with the shark tuner. No more 100psi fuel pressures.

I believe so. They sent me a bunch of extra ones so i think i can stack an other one behind it. I just rebuilt it the way it came...i didnt want to add another variable to trouble shoot if somehting wasnt right when i tested it.

Shark tuner is the answer, but i cant afford to spit out the $$$$ for one right now. Holidays, ...kids...strike preperation..all that fun stuff.
Once i get a few things set, buy the required chips, burner etc, and perhaps read over the manual Id love to dive into it.....
its defintiely the way to go and i cant wait to hear some feed back from those with the higher HP cars playing with it.

I think they were talking about rental.

Strike - Good luck. The way I solve the holidays is that James my three year old gets lots of boxes in the mail. They are "his parcels" and he opens them, and well, sometimes its a cross-over, maybe a piston ring expander, etc. :)

I hope that the SharkTuner will be useful to you brave guys :-)

The s/c cars was the whole reason that it was developed. I must say that some of the very high fuel pressure people are using sound very scary - risk of fire etc. Also, fuel injectors aren't designed for these very high pressures, I have read. So they may not be closing too well at those high pressures...

Even with 42lb injectors you will have to raise the fuel pressure above rated to get the highest power levels, but at least with the SharkTuner you will be able to get a good idle, and map accurately all over the range to WOT. And the pressure rise required will be much less that with the same power and smaller injectors.

There is no reason that a set of Sharktuner optimsed chips could become available for some standard versions of Andy's kit. Then the cost would be reasonable, especially with a SharkTuner rental option.

Work on the EZK version is progressing well !

I'm now going off line......

:cheers:





I had totally forgot about the bleed off, that indeed should allow the air to escape.

If you DO have a more recent revision system with the IC outlet on TOP, make sure you use it as an outlet. I actually finished off a car that Andy had started because he was too busy. We had a miscommunication about which hoses were the input to the washer resevoir and which hose was the pump output. I plugged the pump output to the IC OUTLET (on top) because it made a cleaner hose run. I couldn't get the car to stop pinging, and was totally confused. I drove it to see Andy later that month and he told me my hoses were on backwards ( :banghead: ). After correcting that, the car was solid.

I'd also like to share something that some people don't realize. You can easilly pull back some timing by modifying the coding plug. In the particular example I worked with, I took the coding plug off, opened it up, soldered 1 wire, put it back together, and all was good. I don't remember the details, but the service manuals should have a good diagram of what needs to be done.

Tony: I hope Derek sees your post on the BEGI. Super job laying it out, as always! Oh, and sure, if the intercooler is a closed system with just water, your flow will work. But I can see no reason not to reverse the circulation and have it fill from the bottom, and that would more readily fill the IC.

John: If I proceed with installing the intercooler I now have waiting in the garage and up the boost a bit with a pulley change, I wll need the Sharktuner. As an early Spanner owner, I am watching the development with extreme interest.

Daryl: Thanks for the intake details. Rick Carter has posted some pics of his intake and modded install on the email list, but I don't see it posted here yet. He has an 85, so there is room for the intake on the driver side. Look at this.

http://www.lasotaracing.com/carter/1.jpg
http://www.lasotaracing.com/carter/2.jpg
http://www.lasotaracing.com/carter/3.jpg
http://www.lasotaracing.com/carter/4.jpg
http://www.lasotaracing.com/carter/5.jpg

Daryl,

Your intake is what us later model SC guys have been looking for. Very nice and I will be sending you an email. :rockon:

Bill,
I got the idea from a post on the supermodel site. Ken 85 S, routed his out behind the PS reservoir, much like Ricks. Thanks for the links. There is an existing opening there. I can understand not wanting to cut the car. But to quote Tony. “The first cut hurts the most”.

If you are considering the Shark Tuner I am interested in looking at a “share purchase” if anyone is interested. I can’t justify the cost alone. I like the idea of making our own chips.

Sab, I am not sure but do you have a slight ping? Did you pick up on:

“I'd also like to share something that some people don't realize. You can easilly pull back some timing by modifying the coding plug. In the particular example I worked with, I took the coding plug off, opened it up, soldered 1 wire, put it back together, and all was good. I don't remember the details, but the service manuals should have a good diagram of what needs to be done”.

Anyone working on traction problems? Woody where are you?

Hey Daryl,
The CS 89' auto we play with at 10psi has major traction problems with 295/35/18"s on it, anything you can come up with traction wise would help. I can only imagine what a TS would do midrange at those boost levels...BTW, did I mention that we also sell tires?

I am curious, the CS 89' auto will not spin from a dead stop in a straight line until it hits about 7psi. (about halfway through an intersection) What are the TS guys seeing with an auto and 89' or later gears? Can you boil them from a dead stop? On the CS the tach will stay at redline when it shifts into second, the tires just catch up to the engine. Same thing? I have a customer interested in a TS setup and he wants to know.

Hi Mike,
Well, you can set the coding plug for 91 octane, which will pull back the timing. I can't say exactly how it changes it (probably at high loads/rpm) but hopefully we will find out the secrets of the EZK software in due course.

Hi Bill,
There are 3 SharkTuners in the US at present. DR has the one, he has done preliminary remapping with good results, although with other commitments I don't believe he has done so much recently. One of the others is being evaluated with a fairly standard car, and the feedback has been very useful.

The 3rd is due to be used with a stroker remapping. I expect results will become available in due course.

Now I really am going to be offline for a while :-)

hmmm..well, again, i guess we will see what happens. On Darriens car we have his running with the top as an inlet. However, when i filled the resivour,i filled it to the point that im pretty sure there is little or no air in the system. The resivour as you look at it in the fender has NO air pockets in it.... IF it doesnt work the way it is now, just some minor plumming changes.no biggy

Also, if any one is running the oil seperator that DR sells, there is a PERFECT spot for it under the throttle linkage assembley on the 86.5 cars and the ones that use the similar throttle set up. Pics to follow.

As far as wheel spin and traction control from a stop Dave, if i start it in 1st gear (via 2 on the selector) and put my food down in the same manner and force i would to launch an NA S4, the car will litterally go no where. The tires will spin with little effort. Launching the TS auto takes a bit of gettting use too, but it is very managble.

I here ya about the high fuel pressures john. I hate doing it that way. It was one of the reasons i went to new fuel lines..steal braided and crimpped fittings.
While neither is good, Id rather have a rod break than a fuel line! :icon501:

As far as chips are concerned...I envision a day when we can perhaps call up DR and say,
" i have an 87s4, running 42lb injectors and 11psi boost, send me a chip" :rockon:
or...."an 86.5 with 24lb injectors running 7 psi"...

Perhaps at some point we can accumulate a data base of maps for differnt cominations...when the time comes, DR could pull them out of a library of files and burn thespecific one needed by a customer....just a wild idea

I will say any addition of HP in these cars does take some gettting use to...you can find your self sideways on a freeway on ramp VERY quickly if your not careful. It will bite you at least once...then you will respect it a bit more. Ask me how i know! :icon107:

Ill second that...
does the liner still go on?
No interference with the headlight?

And if you're one of those who needs a second opinion... :(

For you guys with the S4's why don't you go under the rad like Tim Murphy plumbed the inlets for his superchargers? Unless you have the new version with the oil cooler down there, but I think he founds a way around that as well when jorge put his together.

Hi Dave,
I am running an 8lb boost pulley on an Eaton intercooler. My boost gauge reads about 7 lbs. I have an auto trans with the limited slip diff and the car was built for the European market so I am not sure what gear ratio it is. I think possibly a tad lower but not sure. Rear tires are 255x40 ZR 17” Bridgestone B500 SI. On full throttle off the line acceleration, both tires break immediately and spin hard to red line. On the one/two shift the rear end will push out a bit depending on the road surface and settle down from there. Bills posts will give you an idea of the smoke. In my case both tires. The ideal tire for me would be one that will slip just a little off the line. My thinking is to cushion the drive line a little. And I would like to stay with a 17” tire.
Just a side story. Just a few days after I got my car sorted out I took it to the street legal drags. My son and I used to race a car there so no big deal. I really had never floored the car off the line before but put it through just about every thing else. Andy had coached me on how I should drive the car. I pulled up to the start line and could feel the adrenine start to pump. Everything I was supposed to do as far as launching the car went right out the window. I hammered the gas hard and went for second at red line. The car hit second and the rear moved out to the left. I let off the gas to straighten her out and floored it again while looking in my mirror. I couldn’t believe the tire smoke behind me. All of a sudden the engine is missing. Oh S—t hit the rev limiter. Time for third. My time was just under 14.5. I feel confident that I can get into the mid 12s with the proper setup and good air. I was pretty red faced after that run but the car did draw a lot of attention from other racers out there

Tony, yes the liner goes back on. The inlet pipe pushes it out slightly at the top but causes no problems. You will see it in the pictures I send you.

Got them, thanks :thumbup:
I fwd'd them to Darrien to see what he thinks.
Great idea, iw ish i woudl have looked at that also.

Daryl, how about softening the driveline with wrinkle-walls??

For the track (and Saturday nite) only, of course!!:icon107:

You gotta start somewhere
 

Jim,
I first unwrapped the Autorotor today. It was stamped 422 on the side. Being of razor sharp inteeligence, I quickly surmised that I probably have a 422 system. I did an upgrade to the larger intercooler. Assuming there is a 424 Autorotor, what is the difference?

2.2 liter displacement vs 2.4 liter.

Brian, well it’s starting to look like one set of tires isn’t going to do it for all occasions. I have two sets of tires and wheels for my daily driver (winter, summer) so why not for this car as well? Woody gave me some good advice on tires that work for him. Info is on my other computer so will let you know when I get there.
Brian, have you given any thought to Solo 1 and Solo 2 racing? There is a Porsche club in Edmonton who race at the military base just north of Edmonton. Check out there web site if your interested. Google Edmonton Porsche club. I think its time they were introduced to the new and improved 928.

Lex,

What Shane said. The 424 was redesigned early this year which made it about 3/8" shorter. I guess I have the only one. I am trying to get Andy to guarantee the snout won't touch my hood if I have new motor mounts but am not having much luck...

:roflmao: :cheers: It's all good.
I was surprised how fast I hit the limiter in 1st and 2nd, scared the crap out of me. I could get good launches with if i was a bit careful. I was very happy with my Toyo T1S's. A little more $ but good in the wet, good wear and sticky to boot.

Does it make any practical difference (that extra .2 litres)? I tend to almost always overbuild (for the future) but usually never need it. Also doesn't the 928 Specialist SC kit use a newer, shorter, Autorotor? It might be that redesigned 424 Autorotor, which may come in handy if you decided to "crossover" in the future.

The 424 is supposed to be good for an additional 30HP

The 422 stystem from Andy is supposed to be good for 800chp.

DR's is supposed to be good for 600chp.

Maybe DR can jump in here. I think he gave up some hp but gained some room and cleaned things up nicely (understatement).

I think DR's is the 1.7 liter.

Sounds like its more than enough for my purposes. I've got a Whipple I'm putting on Ebay as soon as I get it sorted out. It has the body of a 2300AX (2.3 litre) but has a different case front. I'm waiting for them to get back to me with answers before I list it, but if anyone here is interested, PM me and I'll let you know whats going on.

I have been looking at the Supermodel kit laying on my basement floor, getting a bit excited to get at the install. All of this experitse and experience coalesing on this thread might just be the source of extra courage I need to attack my new '87 S4.

I have a few questions about the kit differences between the" '86 S" kit variant which was how Andy configured the kit.... for a previous car.

Andy told me that I needed to get the "S" throttle body.... which I did.
I now suspect that I need the "S" Fuel Pressure Regulator as well??
Do I still use the M-9593-B-302 #30 injectors that I got from Summit Racing for the "S" installation?

Also, There was some conversation elsewhere about the induction system gaskets. What I have appears to be made from 1/8" thick cork. Is this the right/final material for these gaskets, or do I need to start hunting for something else?

I'm sure that if he sold it to you, it would fit. Andy knows the dimensions under the hood of a 928 better than anyone else. When he designed a GTS prototype kit (from scratch), he didn't even need to look at any of his previous drawings. He just started drawing it in cad. When the manifold arrived and we installed it for the first time, all we had to do was shave a couple mills off a corner and it fit right in.

If you have an 85/86 and use 30# injectors, then using the 85/86 regulators will lower the fuel pressure to give you a better idle.

Hi Mike,

I appreciate your dedication to Andy.
If it will fit Andy won't have any problem with a guarantee that it will. I think he got a bit nervous when I mentioned new motor mounts.
I don't think I am being unreasonable.
:cheers:

Mike,
Brian started out with an 86 928 and was going to supercharge it using the Autorotor SC. He sold that car and now has an 87 S-4. I have an 88 S-4 with the Eaton SC and on Andy’s advice I am using an 85-86 FPR. It appears to be working perfectly. Should Brian use the same FPR as I am or should he use the BEGR that was to be originally used? He is using the same #30 injectors as I am.

Mike can you clarify if these are the right intake/manifold gaskets?

Also, There was some conversation elsewhere about the induction system gaskets. What I have appears to be made from 1/8" thick cork. Is this the right/final material for these gaskets, or do I need to start hunting for something else?

Jim,
What size tire and wheel are you using at the back?

Thanks Mike, but I'm still confused. Could someone just address these 4 specific questions?

For the '87 S4 intercooled Autorotor Supermodel:

what injectors?
what Fuel Pressure Regulator?
what about the BEGI RRFPR? use it or not?

Induction system gaskets. What I have appears to be made from 1/8" thick cork. Is this the right/final material for these gaskets, or do I need to start hunting for something else?

I have parts from Andy's kit I didn't use if someone needs them to do a "stock" install. Originally I said I ony used Andy's intake and pulleys, but I also used his oil inlet.
Rick
85 32v modified with bent valves

Pics of Parts for kit
 

I wanted to take pictures of the kit. If someone wants to photoshop the parts to show 1) what they are, and 2) how they are used (special uses for features:, fittings, holes drilled for each part) that would be a great help to everyone.

Mspiegle,
Did your kit have one pulley only for the crank? When he sold me the kit, he said mine would not utilize the smog pump. Not sure if that is because its an older design or what. Maybe it cannot because its a different design. Many people are saying that two are required even if the smog pump is eliminated.

Hmm... IIRC, you have a kit from his last run. Your crank pulley setup looks much different than what the majority have. I think most people have a larger anodized crank pulley. Is your stock pulley supposed to go inside of the SC pulley?

For the '87 S4 intercooled Autorotor Supermodel:

what injectors? 30lb Ford (I have heard that 23# ones work well too)
what Fuel Pressure Regulator? stock (I have heard Andy liked to have an earlier-model one installed)
what about the BEGI RRFPR? use it or not? Use. Definitely.

Induction system gaskets. What I have appears to be made from 1/8" thick cork. Is this the right/final material for these gaskets, or do I need to start hunting for something else? I see no reason there would be a problem

If you run ford 30#, use the 85/86 regulator

Depending on your setup, you may or may not need the RRFPR. What amount of boost will you run?

The gaskets he provided are probably fine. He's gone through about 5 different types of gasket material.

Thanks Mike!! That's very helpful!

I will not run more than 8 lb of boost..........................
initially :rolleyes:
Can you explain how/when the BEGI becomes significant?

That should put you over 400rwhp, so you'll definately want the RRFPR.

I'm not certain, but there is a chance that if you use 30# injectors and keep the S4 regulators - you might be able to do without the RRFPR by using the sharktuner - but that's uncharted territory.

Heinrich, thank you for responding to this question. I would really like to clarify this issue about what fuel pressure regulator to use and if the BEGI should be used or not.

The injectors we are using were purchased from Summit Racing part #M-9593-B-302 #30.
My car is an 88 S-4 with an intercooler Eaton SC at 8 lbs boost. My last communications with Andy was last August. He told me to dump the BEGI and use only the 85-86 Fuel pressure regulator. In fact I traded my BEGI back to Andy for a pulley puller and new pulley.

My car was also running open loop, (all of the US cars run closed loop) which created problems not incurred before by Andy. I converted my car to closed loop so it would run like all of the other US cars. When going through the trouble shooting of this it came to light the the #30 injectors purchased from Summit Racing are really #25 lbs injectors.

The car is running great. I am using a wide band air/fuel gauge and the ratios are 14s at idle/cruise and mid 12s at wide open throttle.

I would like to know: On what applications is the BEGI used and what applications is it not used? Anyone know the answer to this question?

mspiegle, is there any chance that you can clarify with Andy when it's appropriate to use the BEGI and when it should not be used?
I would really appreciate it if you could.

Damn Daryl :rolleyes:

#1 24 & 30's have been used
#2 85-86
#3 I used it, and needed to with the #30 injectors.
#4 Can't remember, see below.

When I get home tonight I will look at my notes and follow up

Daryl,
If you were running #30 I think you would need the RRFR.

One of the problems is I don't think any one application worked on all the Sharks. The system was morphing weekly and very few of us who actually installed and ran one will have the same experience as the one previous. I have saved most all of the install e mails and will review them when I get home.

if you wanna be safe, just get 30# injectors with 85/86 regulators and the BEGI. I have this setup running perfectly fine on a GTS which has a similar fueling setup to an S4. The car puts down over 400rwhp on 5psi and passes smog as well. This setup is daily driven.

This will also allow for some future expandability, because almost everyone wants to up the boost at some point in time.

You may or may not be able to get away with different and/or cheaper setups. Just do this and don't worry about it later down the line.

If you make the injector bigger, that leaves less reason to need the RRFPR. The RRFPR can only increase fuel pressure - not decrease it.

Thanks very much Daryl, Mike and Jim. This is coming together nicely. One last fuel system question, if you would.

If you look at Rich's '85 car with the custom fuel rail logs, you will notice that he deleted the fuel dampeners. I plan to use the same logs. What is the consensus on the need for the dampeners?

Next issue......... The '86 throttle body I got from 928 Int'l does not have the Closed/WOT switches on it. I'm not sure I can even see where they would mount.

I gather I need them?

Does anyone have a picture of the throttle body with the switches mounted?

It would help to decide what bits I need to order.

You need the S4's.

Uhh Mike, the ARRFPR does indeed decrease fuel pressure...I have run as low as 25psi on the 89' with one. (with 30# injectors of course)

The BEGI2025 unit that 99% of the SUPERMODEL kits use does NOT decrease fuel pressure. IT IS IMPOSSIBLE.

The unit works in tandem with the existing fuel regulators. The ONLY way you can decrease the fuel pressure is to reduce an in-line restriction. Since a restriction is already imposed by the stock regulator - it is physically impossible for the BEGI RRFPR to lower fuel pressure. It can only increase the fuel pressure by adding more in-line restriction.

Please do not confuse people on this thread.

I'll get you one, Brian. I don't think the dampeners are required but hopefully somoene else can chime in to confirm

Are you saying that the mounting will be intuitive?

Wanna bet!! :rolleyes:

You need the throttle switch from an 85/86 car if you don't want to do any modifications. You may use an S4 switch if you drill a hole through it (VERY carefully) and mount it backwards. The reason is because the throttle opens differently on an S4.

You can only use the S4 switch if you physically modify it to mount backwards on the throttle body.

Thanks for that Mike. I didn't remember use the S4 switch :rolleyes:

The fuel dampers are REQUIRED. They are there for a reason. Fuel injector pulses will screw around with the fuel pressure. You may find yourself running lean in certain cylinders if you leave these out. As each injector opens, you get a drop in fuel pressure. The damper eliminates this.

Just get the 85-86 switch.

Just for clarification, regarding fueling requirements for the '87+ cars:

The ONLY kit that may run without 30# injectors for an '87+ car is the basic 4psi stage1 jag/eaton kit. For anything more than that, USE 30# injectors with 85/86 regulators.

Yep

Mike, the BEGI is an FMU. An RRFPR will reduce fuel pressure like any fpr. Also, Tony is running 24lb injectors with more than the basic 4psi kit. IIRC, his 30lb injectors wouldn't idle right, but at least one was bad.

So there Mike, thanks Matt...

Who's confusing who? The BEGI works along the same lines as the Vortech FMU that Tim Murphy uses in his kits.

The Adjustable Rising Rate Fuel Pressure Regulator does exactly that, regulates the fuel pressure and will decrease as well as increase fuel pressure. I used one on a FAST kit that ran 5psi with 30# injectors and it worked fine for the application. I also use them daily for fuel tuning on cars with exhaust mods. I have one on a GTS that has 30# injectors and no supercharger...yet.

Dave and Matt:
I think that Mike is correct on this one......

If you use the BEGI in series with the OEM FPR the lowest system pressure is going to be determined by the smallest orifice (greatest restriction) in the system.

If I read this right......... the OEM FPR cannot reduce the fuel pressure beyond "X". Regardless of how low the BEGI restriction can get, the determining factor for LOWEST pressure will always be "X", as determined by the OEM FPR.

Unless I miss my guess, Dave, your experience is with the FMU/BEGI alone, without a stock FPR in the line?

My car sometimes goes into limp mode. It is rare and only happens during idle and a restart resolves it. Has anyone else had this? We saw this issue on both GT's with the Jag/Eaton setup.

First I have heard of this. Does Cameron's still do it?

Dave,
The BELL 2025 is a "piggy back regulator". It is designed to work in line after the stock regulator it DOES NOT/NOT DESIGNED TO set baseline fuel pressure. Baseline or off boost fuel pressure is still controlled by the STOCK regulator.

Here is a clear and concise statement probably written by Corky Bell about the BEGI 2025 from http://www.bellengineering.net/Pages/products_FPR.html

"The BEGi standard rising-rate regulators are designed to increase fuel pressure and fuel flow in a fuel injection system by augmenting the factory fuel pressure regulator. These regulators must be used in conjunction with a factory regulator, which provides the base fuel pressure (the fuel pressure at fuel rail during idle conditions). "

:rockon: Edit, for those visiting the link do not confuse the 2035 with the
(multi role) MR2035 different animal all together.

You need an fpr in line with an FMU. The FMU only operates or adjusts the pressure under boost. With no boost or under vacuum the FMU escentially goes wide open, that is why you still need an fpr. Mike said the BEGI cannot reduce pressure. He is correct that the BEGI does not reduce pressure... the fpr does.

edit: a standalone RRFPR can reduce fuel pressure like any fpr, and be rising rate under boost like an FMU. The BEGI is an FMU.

...and Mike types faster than me.

Hi Jim, Cameron's does it as well.

Mike, any idea why Andy doesn't like the MR2035? It would clean up that side of the engine a lot!

Do you have an AF meter?

yes.

And it doesn't show you're overly rich at idle?

The MR2035 is difficult to adjust because the baseline and onset pressures are not totally seperate. It's quite large and odd to mount as well. It was tried and the results using #30 injectors, an 85-86 fpr and the 2025 were superior for the 87+ cars.

I find it only useful at acceleration, since at idle or cruise it seems to just hunt up and down. The car does not seem to run rich at idle though.
It shortly drops to red or off the scale on tip in, but then goes rich at full throttle.
It idles perfect, just once in a while it seems to jump into 4 cylinder mode. It happened a couple of times on a very hot DE / track event idling at extreme heat in the pit area.

Daryl:

8 PSI. No wonder you are having traction problems. :burnout: With those AF ratios, looks like you are doing fine as is. Maybe because your car is an S4 rather than GT there are no tip-in issues at this boost level, and as Louie has pointed out, fuel is not really the issue there.

You know Brian, I am 100% sure when I built mine, I remember pulling and swapping both, and the S4 unit fit fine. I also remember Andy telling me I needed the S4 unit on the 85 throttle body. Guess I remembered wrong sorry Dude.

Posting some pics here that might help. The first 2 show the the system on my 90 GT. The second 2 are of pretty much the total parts package.

I haven't pulled the motor yet so if you want pics of specific areas from my 90 GT let me know.
I also have an MX424 sitting on my bench if you want pics of the stripped down system

:burnout:

No problems heinrich...... With all the help here, I think I have the first steps of the install sorted!

The wrenches come out this week-end!

Ok...this is a long rambling, stick with me..I hope it helps.

The BEGI 2025 that you are running IS NOT SET UP TO DECREASE FUEL PRESSURE. PERIOD.

It may do so ONLY if it presents the largest restriction in your fuel system prior to the fuels return to the tank.
In our cars, the BEGI is not the greatest restriction......its the stock regulators. (unless approaching 0” VAC or under boost when the BEGI unit starts working)

The fuel pressure at idle is dictated by the size of the restriction in the line presented by either
1) 85-86 fuel pressure regulator or..
2) 87 regulator.
3) if you want to split hairs ..you can add the health of your fuel pump and system.

From what i can gather, the 85-86 regulators are LESS restrictive than the 87 regulator, therefore allows for a slightly lower idle fuel pressure. (which is why it may be better to run one with the higher rated injectors...30lbs etc) Correct me if im wrong in any of this..!!!!!!.

The restriction that the BEGI unit provides is and ALWAYS will be less than the restriction that is provided by the 2 stock regulators, unless approaching the transition from VAC to boost.


Now..Im curious for those that have the GTs

1)What are your fuel pressures at IDLE
2)at 0 manifold pressure
3)and under boost…and at what boost
4)What size injector?

I ask as it seems common for the GTs to experience TIP detonation during the transition to boost. While fueling isnt the only cause for this, if you are anywhere shy of the required amount of fuel during the transition from VAC to BOOST , you are not helping things. Im thinking perhaps the ZERO point/transition fuel pressure is set to low??


I haven’t seen or heard any real definitive guidance on how to set the BEGI unit on ANY set up that is out there ....except for something along the lines of..."give the center screw X turns...the needle valve Y turns"
If you set up you car blindly like that, IMHO you are flirting with fueling issues.. You need a fuel pressure gauge and obviously an AIRFULE ratio meter of some sort. The BEGI unit seems to be a pretty mysterious object to many of us in the way it works. It is/was to me also until the last week or so…but I think I have a pretty good grasp on the SOB now.

This is how my car is currently set up (YMMV)

1) I have an after market Adjustable fuel pressure regulator. The ONLY reason I used this is I had it on my car to begin with when it was NA….it worked well then as well so I kept it as it determines the idle fuel pressure..
2) I have the BEGI 2025, which you all have.
3) I’m running all fuel dampers.
4) 24lb/hr injectors

VACUUM-SIGNAL LINES
1) the signal from the manifold goes into the barb on the BEGI UNIT shown in the picture.
2) the check valve goes on the barb that is attached to the NEEDLE VALVE. NO TWO WAYS ABOUT IT. THAT IS HOW IT IS INSTALLED.
3)you must obviously have a stock VAC line running to your pressure regulator



This is how I set up my fuel pressure.
(I have accounted for the fact you all are probably running a STOCK 85-86 or 87 type regulator and not the one shown in my pic.)

1) start the car
2) note the fuel pressure, write it down if you like.
3) keep all vacuum lines and signal lines connected.
4) turn the CENTER HEX adjustment bolt on the BEGI unit until its almost ALL THE WAY OUT…..no fuel will come out, don’t worry
5) at this point the ONLY RESTRICTION IN YOUR FUEL SYTEM IS PROVIDE BY THE STOCK REGULATOR…THIS IS THE LOWEST FUEL PRESURE your fuel system can give you (unless your voltage slips on the fuel pump) …my car, with 24# injectors I see 38-40psi.
6) With the car at idle, pull the SIGNAL LINE off the BEGI unit. You MUST PLUG the signal line as you have now introduced a vac leak to your engine. I just tore of a small piece of paper and let it get sucked onto the opening. The BARB on the BEGI unit is left open to the outside air. Since it is now sensing ambient pressure, it is actually sensing “0” as would be seen on a boost gauge as you drove and transitioned from vac to boost..
Get a hex key and start turning the CENTER HEX KEY back in. In doing this you are setting the fuel pressure you would like to see at ZERO boost…0”hg…whatever you want to call it……or the transition from VAC to boost. I call this the ZERO point for my own reference and I set my car to appx 68-70psi. Write down the fuel pressure you set it to for your own records.

7) once set, place the SIGNAL line back on the BEGI unit and note your fuel pressure afterwards. IT WILL DROP. It should drop to the value you saw in step 2.…my case 38-40psi. It does this as the vacuum being produced at idle is be transmitted though the signal line to the inside of the BEGI unit, pulling up on the diaphragm inside and in doing so moving the piston off the face of the metering port in the BEGI unit. The BEGI is not providing ANY restriction to your fuel system at this point….the stock regulators are again in control..

8) NOW……..this gets to the tricky part and actually requires that you drive the car.

The maximum fuel pressure that you see under boost is dictated by the adjustment on the needle valve and ONLY the needle valve. NOT THE BIG CENTER HEX BOLT.
In a nut shell…needle valve all the way in the HIGHER the ending fuel pressure
Needle valve out LOWER the ending fuel pressure.

To describe what is happening with the needle valve is as follows…..
You are bleeding off pressurized air inside the BEGI unit produced by boost. Its this pressure that forces the diaphragm and piston down on the metering port and restricts the fuel flow inside the unit ….thus INCREASING THE FUEL PRESSURE!!!!!
IF you turn the needle valve all the way out, you are letting that air pressure escape and thus reducing the amount of force it can place on the diaphragm and piston in order increase fuel pressure. If you have the CHECK VALVE ON BACKWARDS, you will never get the settings correct as air will NEVER be allowed to escape.

NOW….If you have the needle valve all the way out and you still have too much fuel pressure you MUST install the small restriction tube in the SIGNAL LINE that goes to the BEGI unit.
To explain what this does is as follows…
The restrictor tube does what its name implies…it restricts the amount of air flow and resulting boost pressure into the BEGI unit. With less pressure inside the unit, the diaphragm and metering piston cannot apply as much force down on the metering port and thus cant restrict the fuel flow as much.

IMPORTANT PRINCIPLE…. For any given setting on the needle valve for maximum fuel pressure, the use of the RESTICTION TUBE, will always lower the final fuel pressure seen under boost.


Example…
In my car I had the needle valve 1 turn in from being all the way out with a ZERO point ( no boost/no vac) fuel pressure set to 68-70-psi via the center hex bolt,
When I drove my car and saw boost (7-8psi) my fuel pressure would go beyond my gauge limit of 100psi!!
This told me that since I basically cant let anymore air out of the BEGI unit via the needle valve, my only other choice is to RESTRICT the amount of air coming in. Therefore I placed the restrictor tube in the signal line. On the next test drive, the fuel pressure stopped in the mid 80’s. with the needle valve un touched from the previous run.


I understand that we all have different size injectors, different set ups, fuel pump health and other variables but the steps in adjusting your fuel pressure to run at idle, 0”hg and under boost when using the BEGI are the same as far as I can gather.

Im sorry if this all reads as confusing, but Ive never had a good understanding of how the BEGI unit worked, what made it tick while it was operating and most importantly a proper way of setting it.

While all this was fresh in my head I decide to http://www.svtperformance.com/forums...smile/cwm8.gif it all up on here…
HTH

clear as mud??

L-jet and LH-jet up through 86 regulators run 30-36psi. 87+ regulators run 47-55psi. Everybody seems to look for 85-86 US regulators. Any US 80-86 or Euro 84-86 regulator is the same. The 16V cars have two, so they should be easier to find.

Tony, if you have a adjustable rising rate fpr, the BEGI is redundant. You probably just have an adjustable fpr plus the BEGI fmu.

Its is some what redundent but the fact is that the regulator was meant for a NA car and can only raise the fuel presure by appz 7psi at 0 manfld pressure....not even close to that needed under boost. Also the regualtor i have was NOT made to see boost...only vac to 0"hg. it was used on my car when it was NA.

You see where i have scribbled on the regulator..."38-40psi vac line ON"
if im at idle and pull that line off the regulator, the fuel pressure will only go to 46-47psi max. If i could blow on the port of the regulator and create pressure, it wouldnt change.

Perhasp i used the wrong term describing what the type of regulator it is. :icon501:


:cheers:

Tony that is a wealth of information, more than I've ever read anywhere on the subject, thanks :thumbup:

Yer Welcome. All for the cause.
It was just buggin me that i didnt really know how this key part worked on my car or how to set it...im still not 100% as i have to check the AFR at the fuel pressures i have..

Thanks Tony!! That was an education in itself!

Mike,
I don't know how the this one pulley he sent me is supposed to do complete the groupo, Andy never sent me instructions or comments.
BUT if it were going to go on the outside of the stock crank pulley, what does the v-belt part go to? Maybe the last accesory driven from the crankshaft...?

Q- Is the crank pulley a different offset or diameter for the whipple/autorotor than it is the Eaton/Jag?

Tony
Are you running 36 to 38 lbs fuel pressure at idle? My idle pressure is 29 to 30 lbs. I understood that 29 to 30 lbs to be the number to strive for.

Are the injectors you are using the same ones that some of us are buying from Summit Racing part #M-9593-B-302 #30? My understanding is that these are actually 24 or 25 lb injectors.

Just trying to clear up misunderstandings as we go here. This is information I got first hand from Andy last Aug/Sept. when I did my install.

I need to find out ASAP. If that is the case my 30's are being run on a rear turbo set up and this would be important info for them to have...

The pressures at which they're rated is different, but I don't think the # rating is that far off. IIRC, Ford's 24lb injectors are closer to 22 or 23 at the Porsche spec. The early 24lb Porsche injectors are rated at 22 by GM.

Ya gotta love industry standard specification!! :banghead:

Ok, I am just passing on information given to me by Andy. At the time I was in discussion with John Speakes about Fuel pressures and injector size. These are the numbers Andy told me to quote to John.

I just did some googling. Ford seems to use several different specs, but their 19, 24, 30, and 36 lb injectors seem to be rated at 43.5psi which is the same as the 3bar Bosch uses. The flow rates should be the same, which makes sense since Bosch makes the Ford injectors. If somebody has the Bosch part number for the Ford injectors I can check the Bosch spec.

This is what I have
FMS (Bosch Design II) 30lb injectors Ford Part # FMS-M9593B302

These are the 30# injectors that you want from summit. The have red tops to them. Any 30# injectors in a kit sold by Andy will most likely be using these:
http://store.summitracing.com/defaul...=egnsearch.asp

The 24# injectors that summit sells have a light blue top. I know because I have bought and used both of them.

Tony is using 24# injectors, so he'll naturally have a higher fuel pressure to achieve the same thing that you are trying to do with 30# injectors.

Warren the first v-belt groove on the pulley from Andy is for the A/C belt. It looks like the pulley you have is a two piece design, similar to the stock pullies.

The one I have for the whipple is a one piece design that has a v-belt for the A/C and the rest are ribbed belts. It also comes wth replacement pulley for the power steering pump. I did not have one for the smog pump since I was not using it. HTH

FMS-M-9593-B302 $204.88
Estimated Ship Date: Tomorrow
Warnings Application Show All

Brand: Ford Racing Performance Parts
Product Line: Ford Racing High Flow Fuel Injectors
Injector Advertised Flow Rate (lbs/hr): 30
Injector Advertised Flow Rate (cc/min): 309
Quantity: Sold as a set of 8.
Injector Impedance: 11-18 ohms
Driver Type: 12V saturated circuit
Overall Height (in): 3.045
Seat to Seat Height (in): 2.563
Manifold O-Ring Outside Diameter (in): 0.545
Fuel Rail O-Ring Outside Diameter (in): 0.523
Outside Diameter (in): 0.982
Injector Plug Style: Bosch/Amp Style
Wiring Harness Included: No
O-Rings Included: Yes

They're either rated at 39 or 43.5psi. If they're rated at 43.5, they're the same as regular Bosch/Porsche. If they're rated at 39psi, they'll flow slightly more than the standard Bosch/Porsche injectors. The Jeep sites all say the FMS/SVO injectors are rated at 39psi. FiveO says their injectors are rated at 43.5psi. My Bosch reference file only has Bosch part numbers, not Ford numbers to cross reference.

Your first question:
From the looks of what you have, the largest circular pulley is for the AC (IIRC), and the smaller ribbed pulley bolted to it is for the SC. Now, my question is if you can take the stock pulley, place it inside the center of the SC pulley, and bolt the whole thing up as 1 piece. Does that make sense? I'm thinking if he mentioned something about blocking the smog pump, that's because when you put the stock pulley inside of the SC pulley - the SC pulley will block the rib used for the smog pump. Does that make any sense? This is ALL speculation. I have never seen that pulley design before, and haven't specifically asked Andy about it... but its the only thing that makes sense to me at the moment.

Your second question:
The "normal" pullies (blue anodized ones that most of us got) work on both the autorotor and jag/eaton superchargers. I assume the pulley you have will work the same as well.

Mike,
Can you clarify this business about the #30 Red injectors actually being 25 lb in our application? Andy told me to use this figure when talking to John about fueling.

Talk to John about fueling? I think I lost you there. Give me an idea of what you're trying to do and I should be able to steer you in the right direction.

Sorry about the confusion Mike,
I thought you would get what I was saying by following the previous threads. I am seeing this thread as an opportunity for all of us with supercharged cars to really get to understand how all of the components work together as well as learn what others are doing to improve there cars. I am looking to you because you have been kind enough to participate on this thread and I think you have the most knowledge of all of us about the different combinations Andy offered.
In my mind proper fueling is now the most important aspect of what we are doing and we need to understand exactly what is doing on with our cars. I don’t want to be a pain in the ass about this, I am just trying to have a clear and through understanding about what is occurring in my car. I understand that 14.7 air/fuel is great for cruise and 12.5 is great for wide open throttle and this is what I am achieving. But to be totally frank. My car just sounds a little off at idle and when in park under light increase in rpm to about 2000 rpm I can feel a slight roughness and I can hear it in the exhaust note. Most people would not notice or possibly care and I was prepared to live with it myself, but I am hoping that through this thread I can learn more. I am now interested in playing with injectors, computers, and total engine management. I didn’t know a dam thing about these things but that’s exactly what I said when I bought my first 928. In email conversations with John Speakes It became apparent that he needed this information in order to offer an option, so I am thinking this is critical information to those interested in improving the drivability of our cars over the total rpm range. I am trying to understand why Andy told me the red #30 injectors which every one believes to be 30 lbs are actually 25 lbs. in our application. Sorry about rambling on. :soapbox:

Tony, thank you for your thorough write up on the BEIG. The only thing mysterious about all of this is the lack of knowledge and understanding. :rockon: I just love these happy faces!

The next question is the bypass valve.

Is it adjustable and how?

I had several instances where my car would dump all the boost when boost is what I wanted. This usually happened when I put my foot into it at low rpms. If I reved it up a little at part throttle and then slammed it home the bypass wouldn't open. It was a weird phenomenon, that went away after I resealed the manifold.

Speaking of resealing the manifold............

I got my manifold from Andy preassembled with the intercooler, and powdercoated. Should I dis-assemble it and re-seal the 1/2's before the install?

Daryl:

Not to be flippant, but 25 or 30, they seem to work properly for most of the setups with the stock 85 regulator. My fuel curve is perfect and yours appears to be too. Be careful that the light throttle off-idle behavior you are observing is not just a characteristic of the stock fuel map. The car may have a slight miss under these conditions. I don't mean to dismiss this if it is more than that, but it easy to notice things you didn't before because you are just paying much closer attention. However, it could be evidence of a slight vacuum leak leaning things out a bit more than normal. How is the idle itself?

Any Canadians have a spare of either the '85-'86 WOT switch or fuel pressure regulator that they want to part with?

Brian that looks pretty cool :thumbup: ... Mine came with a mammoth gap between lower plate(s) and IC, but there was a thin bead of sealer inbetween ... you coud see right through. I don't believe you have to undo the whole thing if you'd like to add a nice thin bead around the edge before torqueing?

Brian:

That's super purdy.

You need one of my throttle cable brackets? I'm making some more this weekend.

Brian Donaldson of San Diego made a much more elegant bracket for his Autorotor. If he is reading this, maybe he could post a few pics. It looked much nicer than mine, seemed simpler to build, and did the job at least as well as my contraption.

bead of......................... ???

<<<<<<Tony wrote:

Example…
In my car I had the needle valve 1 turn in from being all the way out with a ZERO point ( no boost/no vac) fuel pressure set to 68-70-psi via the center hex bolt,
When I drove my car and saw boost (7-8psi) my fuel pressure would go beyond my gauge limit of 100psi!!
This told me that since I basically cant let anymore air out of the BEGI unit via the needle valve, my only other choice is to RESTRICT the amount of air coming in. Therefore I placed the restrictor tube in the signal line. On the next test drive, the fuel pressure stopped in the mid 80’s. with the needle valve un touched from the previous run.

End of what Tony wrote>>>>

When you pull the vac line off the BEGI you should also pull it off the fuel reg as well to get a true reading.

I would think that 68-70 psi at zero manifold pressure is going to cause a rich condition at all times when you are not in boost. This will result in poor drivability and fuel economy. I would leave the needle valve closed and use the BEGI onset adjustment to tune where you want your final fuel pressure to be when you are in boost. Once you do this you will know what the initial setting should be. With the needle valve closed you would be at 8:1 fuel to boost ratio. You might find that you will have it set very close to where the stock regulator would be at with zero manifold pressure. If this were the case I would dump the BEGI and put in a std Vortech FMU which is a more reliable component. FWIW, the needle valve will have minimal effect with out the restrictor on the manifold signal line to the BEGI unit.

Sorry, permtex gasket maker or such.

:confused: Tim ....

Too true! That is how I got my car tuned, and Tim, THANKS for helping me over the phone to get it that way.

I have an unused Super FMU I bought in preperation for installing a F.A.S.T. system but didn't.

I'd be interested ... price? I currently have a BEGI.

Heinrick you have a Vortec super FMU.

Bill

I just have to say: “You are the man”!
This is a very difficult decision because there are so many good people out there but…

I hear by nominate you Rennlister of the year. I don’t know anyone who offers so much good advise and potential causes than you do. I really appreciate your input.

I think I hear what you are saying. If I have covered all of the bases, vac leaks, mechanical possibilities, then just get out there and enjoy the car. It probably ran about the same as before anyway. You know you are right, but I don’t live in sunny California. We just got about three inches of snow and they say more is coming! And business is slow on top of that. How about I put my car on the trailer and get down there for a nice visit?? Oh, you don’t have any extra room in the garage!

Seriously though, when I first got my car it was a vacuum leaking sieve! Every actuator leaked, the modulator leaked, both dampers leaked gas, the intake manifold gasket leaked and probably a few other things I can’t think of right now. As well I had one dead injector another that had to be replaced and the rest serviced. I became very sensitive to how the engine ran and I know for sure it’s not quite as good now.

I borrowed a smoke machine and I don’t see any vac leaks. I think that is covered off. The only other thing I noticed is that when I short number six plug the engine does loose rpm but not as much as the other cylinders. The spark plug look good and so does compression. I am going to pop the injector and have it checked out. From there I am on to fuel mapping. Anyone want to join me???

One last question? Are our red #30 injectors 30lbs or 25lbs. when used in out application. Ouch that hurt! Someone just threw something at me. Was that you henrich? :)

Coulda sworn that was a BEGI! Oh well :)

Brian,
Many of used this stuff

http://www.permatex.com/products/pro...&item_no=33694

You can get the size that works in a regular caulking gun.

Yep, If you are going to reseal. Putting a 'nice clean bead' around the outside probably isn't worth the time. I probably wouldn't reseal.

Daryl:

Another thought about the slight off-idle roughness. I sense the same thing if I am sitting in the garage in park or neutral and gently push the throttle under no load. However, when driving, there is no uneveness at all even gently taking off from a stop or cruising along in traffic at under 2K RPM, so I have chosen to ignore the no-load uneveness. I can't recall if it was there before the SC.

Bill,

>Another thought about the slight off-idle roughness.

Have you tried adjusting the position of your TPS? If I recall it should come "off idle" at only 1 degree from idle and yours could be out of adjustment.

Bill,
I would would swear you are describing my car exactly! I can also hear a slight difference in the exaust and not quite as smooth as before. I think the computer is working hard trying to main the 14.7 air/fuel ratio.
Please don't forget me on the throttle upgrade.
Thanks

Daryl:

I've posted before that I do have a persistent IDLE roughness when the car heats up. It has been traced to a drop-out of cyl 7 ONLY AT IDLE. Once off idle, cyl 7 fires normally. I have had this since immediately after the SC install and have not found the cause. The car dynos and drives perfectly OK otherwise and has had 10K miles of care-free driving under all kinds of conditions including 100s of miles in the desert almost flat out. So, someday I will probably find a heat-expanding gap somewhere. I am going to get into this when I install the intercooler sometime this winter. Until then I just drive it daily. It's outside here at work waiting for me to drive the 40 mile trip home tonight. Guess I should get back to work for a while....

Just because its pre assembled doesn’t mean its sealed. The best way ive found is to run some masking tape around the perimeter of the seem leaving appx 1/4 inch of the seam exposed. Then take some sealant...i used "The Rightstuff" and apply a light, thin bead of it along the entire seam. then take your finger (wear a latex glove or something) and smear the bead flat and smooth..filling in any gaps or question able areas.
Once done, remove the tape and your left with a really nice neat bead of sealant along the entire perimeter. :thumbup:

With the nice red manifold you have you want to keep it as neat looking as possible!
Looks great!

Tony that was my thinking too :thumbup:

Thanks Shane. Its interesting how Andy goes from multiple pulleys down to one. It must be the K.I.S.S. method finally dawning on him late.

Yes, put the SC pulley so it covers up the air pump pulley. Then the last v-groove fits the AC compressor. I think I got it.

That's a very nice design I think, better than the one I received way back ... I'd say (eh Tony?) just make quadruply sure you get the bolt torqued and it doesn't come out.

Hmmm..good idea, i will try that but The after market fuel reg i have, that was on my car NA, will only give me a max of 6-7psi gain with the line off.



I basically never new how the darn thing worked to be honest with you. Not until i tore it appart and took the time to study it a bit .

On that note...how many of the TwinScrew set ups are currently using the restrictor in the signal line?

Now that ive figured it out (i think) i dont know how you could NOT use it. It made a HUGE difference in the needle valve adjustment (final fuel pressure under boost)

Funny thing is, i think thats how i WAS doing it, when i couldnt get a response from the needle valve adjustment. On some reading, a whim and some experimenting i decided to try the restrictor ....the needle valve works as advertised now.

What is the differnce between a VORTCH FMU and the BEGI unit then?
dont they do the same thing?

Also..the 8:1 ratio...i assume that is above a stock value?
ie: 5psi boost is in acrease of 40psi fule pressure at that level over stock.
Why is the value it 8:1?

Bill,
I forgot to mention that when my car is cold it runs perfectly, only after it warms up does the slight roughness start.

Geeez, did you have to mention that you get to go for a 40 mile drive in your car today?? I suppose the temperature is about 70s?

Here is what I am looking at out my front door right now!

got the same issue here.

Tony
Interesting that you have the idle issue as well. I wonder how many others are experiencing the same thing? Have tried to diagnose why?

Wow. With all the resealing Tony did, if he has it, then there is something systemic. Mine is very clearly a cylinder 7 miss. When the miss starts, it is a stumble at idle in gear at stoplights. It is worse in park or neutral - a virtual complete drop of cylinder 7. You can hear it in the tail pipe and the car shakes mildly. If I pull the spark boot and/or the injector lead to 7, there is no change at all, whereas all the other cylinders show a response to a pulled lead. Swapped injectors, new plugs, wires, etc. It's always cylinder 7. Hit the gas - no problem. I keep thinking something is leaning out #7 at idle when warm - perhaps related to the bypass passage which is nearest 7. I have not gotten any further with this. As I said, the car runs so well under any kind of power, only stumbling at idle, that I have not pursued it vigorously, especially since it's such a stumper with no clear cause.

Daryl:

Looks like a warm day for Saskatoon in December. When I was single I had a brief fling with a girl from Saskatoon and went to visit her one April. April, you know the month when things generally are blooming around most parts of the world? Jesus HC! I thought we had returned to the ice age! It was truly glacial weather. It was the first time I had seen these things you mount on the inside of your car door windows so you can have any hope of seeing out of them in the subzero high for the day. I'm still shivering.

Tony,
I'm way ignorant on these voodoo fuel pressure regulator devices, but it may have something to do with the relationship between fuel injector inlet pressure difference and fuel injector flow difference. The flow through the injector isn't linear with relation to a pressure change to the injector. IIRC, it's something like the square root of the pressure ratio. Going from 40 lbs to 44 lbs = 44/40 = 1.1 ratio in pressure. Sq. root of 1.1 is 1.0488. in this case a 10% increase in fuel pressure gets less than 5% increase in fuel flow. That's why fuel pressure has to increase more than air pressure. Even then it's logarithmic, not a straight multiplication like 8:1.

Do you mean, DO NOT disassemble the manifold 1/2's, but do this process to the perimeter of the assembled unit?

Thanks Louie, i had read that also, just wanted to get those that are really familiar with it to perhaps shead some light as well.
Its a whole lot of pressure.......extra pulse duration is the way to go :rockon:

I am curious what makes the VORTECH FMU differnt from the BEGI unit however?


Brian...If the assembly is already together, dont take it apart. I didnt on Darriens, but i did see some areas that didnt give me the warm fuzzy. So instead of just tossing it on and perhaps chasing a PITA vac leak for a few days, i decided to check everythign over again myself and resealed the perimeter. You dont have to take it apart. I have found that the rightstuff tends to litterally squeeze out of the two halves...inconjuction with boost...vac...boost...vac...heat....etc..id expect it to eventually fail.
The sealing of the perimeter on the outside is just another line of defense agains leaks IMHO....the less leaks the better. :cheers:

Ounce of prevention is worth.....

IMHO...DEFINITELY IS Bill .
where im not sure.
Like you, its minor and im just driving the piss out of it :evilgrin:

The tires dont care for it but the engine/SC sure loves boost on these cool 40'f mornings!
F'N screams! ..really does
:thumbup:

Hi,
I've been away for a few days R&R, so have a couple of comments...re idle quality.

For people like Daryl who are running the 30# units with an 85/86 FPR (30psi at idle) , the sums look like this -

As Louie says, the relationship between fuel flow from an injector for a change of pressure is a square law one. Double the pressure and the fuel flow increases by sq root 2 = 1.4times flow.

This is why the fuel boost WOT fuel pressures have to go so very high to get the flow required.

If you apply this to running a 30# injector (which is rated at that flow at 43.5psi) at 30psi,then the actual flow calculates as 24.9#. This is as stated by Andy.

This means that at idle, instead of running a standard S4/GT/GTS 19# injector, you are running the equivalent of 25#. This may seem "near enough" but in fact the fuel flow is more than 30% higher than it should be. This means you are running at or beyond the adjustment range of the O2 loop, depending on other variables in a particular car.

This may explain some of the hot idle problems people observe.

It would be simple to readjust the idle fuelling with the SharkTuner. A better approach might be to revert back to a standard S4 fuel pressure at idle (47psi) and then optimise idle and cruise fuelling with the Sharktuner. This wouild then mean the 30# injectors are running at their design pressure, and therefore the flow patterns would not suffer as they may be when running at only 30psi

Regards

Bill, I am sure you will find it when you go looking for it. May I recommend you check your injector wiring harness? when I did my SC install I found one of my pigtails pinched between the head and the cam cover. I had to repair the insulation on one of the wires in the pigtail. the eratic idle symptom went away when I did that......just a shot in the dark.

When i chased a gremlin down, i replaced all of mine Gretch..i still get it.
no biggy at all, just not perfect.

John, thanks for that info...good stuff.
I would actually like to place the stock 19lb injectors back in to see if that changes the situation...granted i wouldnt be running around with my foot in it all the time, but im curious to see if they would make a difference and return the idle back to "normal" atleast. :cheers:

Hello John,
Thank you for responding. I hope you had a great holiday. Your explanations make perfect sense to me now and easy to understand.

When using the Sharktuner do I need to log the engine performance with another device first? When changing to the stock 47 psi fuel pump do you see any reason to use the BEGI? Or for that matter do you see any reason to use the BEGI at all? Do we need any other fuel controls other than the stock fuel pump and the two dampers? When will the Sharktuner with timing control be available? I don’t have a serial port on my lap top only USB ports.

Do you have any thoughts on this issue of a dropped cylinder that Bill is alluding to? The test is shorting out each cylinder one at a time and seeing what the engine RPM does. In Bills case number 7 makes no difference to the idle speed. In my case number 6 makes very little difference to the idle speed but does change a little. We have checked compression, the spark plug looks normal and there is no question that we are getting all 8 cylinders under all other operating parameters. In my case I still need to have the injector checked out but I believe Bill has done that with no change.

I am very interested in tuning with both fuel pumps to see the difference but also tuning different combinations in open loop as well.

Bill,
Now you know why I am trying to find a 928 event somewhere south in January or February. Ok, March, April, or May as well. Actually we can get some nice weather in April and May.
She must a have been a knock out to drive that far and endure such cold weather. Hope she kept you warm while you were here!

Who said global warming is a bad Thing?

Daryl & John:

Yes, I tested compression and swapped injectors and leads to rule out anything inherent in cylinder 7.

So, John, are you saying we are running too RICH at idle. The plugs sure don't show that at all. If anything they look lean, although I'm not holding that out as diagnostic. I got a little confused reading your explanation. We are running 30 lb pressure with 30 lb injectors, and that results in too much flow at idle. So, at 30 lbs, below the injectors rated pressure, they are erratic and they would be better at 47 lbs with a lower duty cycle enabled by the Sharktuner, something the LH cannot do on its own? I can buy that explanation as it would explain why there are no drivability issues at all once the throttle is down, the pressure comes up and the injectors are happier.

Hey Bill,
What about the girl from Saskatoon? :D

John, I too thought that running an S4 at about 2/3 of stock fuel pressure with 30% greater injector flow would put is back to near-normal fuel delivery into the cylinder.

She ran a little rich at idle too.

Bill said,
"So, John, are you saying we are running too RICH at idle. The plugs sure don't show that at all. If anything they look lean,"

On my car it runs great cold and gets worse as it warms up. Which seem to me it wants a richer mixture when warm.

Bill,
Ok,,, I understand. Didn't anyone tell you, many of them run in open loop in this Country. And no Cats I might add.

With 30 pound injectors my 85 idled at 14.5 as indicated on wideband, rich at 3000 and lean at 5000-6000. I don't remember the idle fuel pressure. I'm delayed going to the dyno to tune with the SMT-6. It was checked repeatedly for vacuum leaks using propane. A slight stumble at 2000 was eliminated after the SC install, I think it was from a small vacuum leak. AfterI've been to the dyno I'll post my fuel pressure and SMT-6 settings for reference.

Hi Rick,
I tried propane and starter fluid but I found the most effective way to find air leaks is with a smoke machine or a smaller diameter tire tube cut open then stretched over the intake inlet and clamped tight then roll up the other end and clamp tight so it doesn't leak. Put a few pounds pressure in. A hose or piece of vac line held to your ear to listen through works great.

how does the smoke machine thing work? i've always used started fluid but it gets expensive after a while

I've been too busy to read through all of the info but if you're into the SC system this thread is becoming very valuable. Thanks to everyone contributing. :cheers:

OK, I'm saying that the fuelling will be on the rich side, but in practice you are all running closed loop. So you will have 14.7:1 I am saying that you are running very near the limits of range of the O2 loop, and this may cause a problem. If your MAF is well aged, this will help the situation :-)

For the first couple of minutes after a cold start, the car runs open loop, and the mixture will be too rich, but when the engine is cold it likes plenty of fuel anyway. When it warms and gets on the O2 loop, it will just about keep the idle mixture under control, if you are lucky.

In the UK most of our cars run open loop and fuelling errors are much more apparant !

Hope that helps.

Daryl,
I don't have enough time today to answer all your questions. Depending on your max power level, you probably will have to raise the fuel pressure at max power levels to get the flow. The sums are easy enough to do. If you need specific scenarios working out, I will do it for you.

Bill,
Yes, the SharkTuner allows you to reset the idle pulse width so you can run bigger injectors at idle, at their rated pressure and get the mixture correct. Above idle, your various RRFPR and other devices take over the control of fuelling by changing the fuel pressure from stock. You would be able to get closer control of the mixture through the entire load range by remapping. You probably could simplify the fuel system by eliminating some of these devices.

The development car runs 42#injectors with a stock S4 fuel system No RRFPR or other device. It is fully mapped up to 495HP crank. That's just an example.

Regards

>how does the smoke machine thing work?

There is a heating element that heats up a fluid, usually Triethylene Glycol (refined anti-freeze) and it turns it into "smoke" (steam)... sorry, I was having flashbacks from the ole Disco days!

You seal the throttle body etc just like a vacuum test but instead force smoke into the intake system, where ever you see smoke coming from that is your leak. Actually you can buy cheap "disco" smoke (fog ) machines cheaper than automotive version and they work great.

thanks for the explanation =)

Who makes the automotive version of these? They must be seldom-used items because I don't recall seeing one in my local parts store.

>Who makes the automotive version of these? They must be seldom-used items because I don't recall seeing one in my local parts store.

No, I don't think you will find one at "Pep Boys". I don't recall the brands, I am pretty sure Mo Zahr (Marc White's cohort) at Best Mechanical Werks has one and I think Joel at North Point Foreign Auto has one too.

For the best deal on the "disco" version, try Ebay. Should be able to get one for under $100.

Mike,
Do a Google search for automotive smoke machines. I would be surprised that any progressive diagnostic shop would not have one.

I just checked with my Wholesale tool supplier and they have some OTC brands starting at $750 wholesale (retail is $1199) .

Here is a quote from the product page ..

" Speaks to the need of highly popular “smoke” diagnostics at an affordable price. "

:rolleyes:

And, a "disco version" on Ebay, it is made by "American DJ" ( I used to sell their stuff ages ago), Buy it now price is $79.95

http://cgi.ebay.com/American-DJ-Fog-...temZ7373563270

Just search "Fog Machine" on Ebay, there are tons there.. FYI, we stopped calling them "Smoke Machines" back in the late 80s because the term "smoke" was too related to FIRE and this made the Fire Marshals much happier and easier to deal with :-).

Cool
Tommy Chong

Daryl,

Did you experiment at all with positoning the filter below the fender brace, where the horns are normally located?

There is no air flow inside the fender. So...
I wonder...

How much cooling you would lose to the brakes by venting some air from the spoiler brake tunnel?

Jim,
Thank you for starting this thread!
I am down to figuring out this slightly rough idle Bill, Tony and I are experiencing. How is your car running? Could you do a simple check? Short out each cylinder one at a time and see what difference it makes to the idle of the engine. It’s really easy at the distributors. On my car when I short number 6 there is very little change to the idle speed. On Bills car there is no change when he shorts cylinder number 7.

On the air filter, don’t forget the horns bolt on under the filter. The picture is at a rough in state. I ended up positing the filter so the end of the filter rests on that tab you see sticking up just behind the filter. When I tightened every thing down it was very solid and secure in that position. I was able to remove a filler piece in the spoiler to allow more air in. I tried to show that in one of the pictures but the angle is very awkward.

wow! them be some crazy smoke machines. Thanks for the info!

DR:

Do I need the DUAL 400 watt smoke machine or can I get by with the 450 watt El Cheapo version? It includes a wired remote. Now, let me see if I can find my platform shoes and red velour disco bell bottoms. :eek:
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7375050955

Just how do you get the smoke into the intake with one of these things? Is that where the disco pants come in? :confused:

Bil, look at your avatar ..... :confused:

Yeah, Heinrich, you'd think I would understand smoke machines.

Bill,

>Do I need the DUAL 400 watt smoke machine

Only if you want to do 2 928s at once :-) That was just one I picked at random..

> or can I get by with the 450 watt El Cheapo version? It includes a wired remote.

That will work.

>Just how do you get the smoke into the intake with one of these things?

Most of them have flanges that you can attach hoses to, then attach the hose to your throttle body (make sure it is open) or other inlet to manifold, etc.

Will this smoke generator only indicate relatively significant leaks in the intake manifold area, or does it create enough indicatior to demonstrate leaks in smaller and more remote components like vacuum pots or switches in things like the HVAC unit, vacuum accumulator, or cruise control unit?

Daryl,
Thanks, it's working out pretty good!

I think you are wanting a SC'd motor to test and I don't have either one of my SC's on right now. I was considering installing one this week end but I am not going to be able to :mad: .

Hi Brian,

>Will this smoke generator only indicate relatively significant leaks in the intake manifold area, or >does it create enough indicatior to demonstrate leaks in smaller and more remote components like >vacuum pots or switches in things like the HVAC unit, vacuum accumulator, or cruise control unit?

If you use a small booster "duct fan" (or the "air out" of a shop vac) to build more pressure I have seen even small leaks around the throttle plate shaft seals.

There is an easier and quicker way to check for leaks. Cut a section out of a rubber inner tube with the valve in the middle and clamp it over your throttle body (again make sure Throttle is open), mass flow sensor, etc. and use an air chuck to pressure it up to about 5 psi. Then use a spray bottle with a mild soap solution to spray on the suspect areas, just like looking for a leak on a tire you will see bubbles where the leak is.

hook a hose from your rear tires!

Thats the route ive heard of to, but ive always wondered about the valves. During engine rotation is there actaully a time when ALL the intake valves are completley shut...
my guess its the 45' mark where you set it to remove the belt. At this point are the valves shut or is Porsche just saying they wont make contact or cause damage when the belt is removed?

Am i missing somehting obvious or does that make sense? :confused:

>hook a hose from your rear tires!

:burnout: :burnout: :burnout: :burnout:

Thanks for that Dave!!

That sounds somewhat safer than my original idea of hooking up a propane bottle to the induction system, for pressure, and then searching for leaks with a match! :burnout:

Tony, plug the tailpipe?

:cheers: Actually, if (like me) you've always wanted to share a good Cuban with your Porsche .... this may be the golden opportunity :biggulp:

Tony,

>Thats the route ive heard of to, but ive always wondered about the valves. During engine rotation is there actaully a time when ALL the intake valves are completley shut...

If you think about it , only 16 of the valves really need to be shut. For example if the intake valves are open on a cylinder and the exhausts are closed the air is still not gonna leak out quickly (unless you have severe ring blow-by)

I have never positioned the engine any specific way when testing this way. Maybe I have just been lucky the last hundred times I have done it over the last few months :-) I have also be able to get my completely assembled SC intakes including everything (TB, MAF, tubing, etc) but the filters to hold 20 inches of vacuum for 45 seconds or so.

If you have big enough leaks so that the intake system will not hold pressure, then attach a leak down tester to the inner tube valve and adjust the output to a constant 5psi, then use the spray trick. BUT if the leak is leaking that bad you WILL hear where it is coming from.

Brian,

>That sounds somewhat safer than my original idea of hooking up a propane bottle to the induction system, for pressure, and then searching for leaks with a match!

PLEASE tell me you are kidding....BOOOOOMMMMM :-)

Tony: I understand we have no valve overlap, so the manifold should be air tight. If the intake valve is open, the cylinder will fill, but that's all. No need to plug the exhaust, even if you could.

Hey What you guys smoken,
Got a few minutes to bug you guy’s.

Dave, thanks for the tip on how to apply continues air pressure. I was going crazy adding air then running around the engine listening. As well I was loosing a very little by the rings, I could hear the air through one of the vent hoses, and that added to the difficulty of holding pressure and knowing for sure I found everything. The engine had not been run for a few days. Probably a good idea to do this on a warm engine. I liked the smoke because I could just stand there and watch. I had a very small leak where the idle valve attaches, just needed to tighten the clamp. Missed that with the air pressure test. After using both methods I am certain I don’t have leaks.

Dave, are you aware of any one who has a TS car and has a slight idle roughness. My car as well as others have this problem. It’s minor and very easy to live with but I want to fix it if I can. I have some ideas as to why but I am not sure if this is a problem on all of the TS cars. If it is then we know for sure it’s inherent in all cars and when someone finds a fix we will all benefit.

What we are doing is shorting each spark plug one at a time and observing the change in idle. In my car there is very little change in number 6 and Bill has no change in number 7. We have done all of the obvious checks, compression, injectors, etc. Any thoughts you have on this? Any thoughts anyone have??

Hi Daryl,

>Dave, thanks for the tip on how to apply continues air pressure.

No problem, glad to help.

>As well I was loosing a very little by the rings, I could hear the air through one of the vent hoses,
>and that added to the difficulty of holding pressure and knowing for sure I found everything.

One word of caution, if you have the "charcoal system vent hose" (the one that goes to the small electric valve below/under the upper rad hose connection) hooked up be sure to crimp this closed if testing without the ignition switch on. With the switch off that valve is open and therefore creating a vacuum leak. I think my system is the only one plumbing this line in like the factory so it may not apply to your system. BUT, if it is plumbed into your system it will drive you crazy during vacuum tests unless you plug or crimp it closed.. I speak from experiance (Grrrr)!


>Dave, are you aware of any one who has a TS car and has >a slight idle roughness.

Only the ones I have read about here. I had some issues when I was experimenting with not using the Idle Stabilizer at all, but it was more of a cold idle issue.

> It’s minor and very easy to live with but I want to fix it if I can.
>I have some ideas as to why but I am not sure if this is a problem on all of the TS cars. >If it is then we know for sure it’s inherent in all cars and when someone finds a fix we will all benefit.

Once I am finished with all my Kits I should have lots of data because of all the different configurations I have tried and the issues of each and will gladly share it.

>What we are doing is shorting each spark plug one at a >time and observing the change in idle.

Try just pulling each fuel injector connector plug off one at a time to see if it changes anything. I find this much easier than dealing with the spark plug wires.

I would also suggest a fuel injector probe to verify injector pulses. Here is the one I use (link below) and it is the handiest gadget I ever bought. You just touch the tip of it to the injector body and it beeps and flashes for every pulse. I was so impressed we now sell them, but they are available lots of other places too.

https://www.928gt.com/ps-26015-30-el...ick-probe.aspx

Hope some of this helps, and have a Great 928 Weekend!

For all practical purposes we have Darriens car set up and running. His exhibits a very good idle as far as RPM....better than mine!..but when it gets warm, it too has that little bit of lumpiness to it as well. Minor in the big scheme of things. Would be nice to get to the root cause.

24lbs injectors...39-35psu fuel pressure at idle

:icon107: First run 0-60mph...5.1sec..with a 2.4sec 60ft time. We have atleast 2-3 tenths on the table yet . Its a sub 5sec car.:icon107:
Measured with my GTECH PRO RR. As not to hijack..More in another post later :thumbup:

Good job. So Tony did you know the 951 boys .... they run 51lb injectors :icon501:

How do they control the low end..idle etc?

Maybe we can learn something .... they also have ridiculously low compression. Sounds like everything we wouldn't do. Yet ....

Checkit -- 55lb http://www.gururacing.net/Injectors.html

It's about a supercharged 928, notta hijack :burnout:

Tony,
Congrats on getting Darriens car up and running. If and when you can find the time would you please do the shorting of each plug test after the engine is good and warm. It’s very easy pulling each wire at the distributor. If there is an issue I think it will be on the left side number six for me and number seven for Bill. I want to at least know what’s causing this before we start with computer mapping. I would really appreciate your help in this.

Anyone else running a TS please let us know if you are experiencing this idling problem or "NOT".

Thanks,

Course they run Motronic. I was wondering if Garrity might have a thought.

Pulling the injector connetors is what the WSM recommends for finding non-firing/injecting cylinders and it hurts less than spark plug wires. :icon501: If you're doing a lot of injector checking, Dave's injector probe is very handy. I saw it at SITM last year, very cool toy.

I've wondered how hard it would be to convert a boosted 928 to Motronic. The programming is much better known and it handles boost. The other OEM system I've thought about is SAAB Trionic. It is fuel injection, ignition, and a boost control in one box.

Matt, I think Sterling has some experience in this regard, but I think he may have bad news for us.

I thought he used Motec M48?

yes ... and it was no walk in the park

Just for the record, I have pulled the injector wires and plug wires individually and together. When the idle is lumpy, pulling either or both on cyl 7 does not affect the idle speed. On all other cylinders there is a drop. Pulling the injector wires is hampered by heat in the area. So you need leather gloves or some kind of tong to wiggle the wire plug off the injector.

I'm sure hoping John Speake is on to something when he speculates it is the injectors being run at too low a pressure at idle to get a proper stream when warm. Cyl 7 just happens to be the one on the edge in my car and it drops out.

Try swapping 7 with another Bill ...

Bill,
I am thinking exactly the same as you along with the added air from the bypass. I just hope the increased fuel pressure will be all that’s needed. I like John’s solutions best so far!
I hope a few people who actually have a TS on their car will verify this for us.

if they have fewer cylinders and therefore fewer injectors - wouldn't it make sense that they need large injectors to flow more fuel for the same hp as a 928?

Ahh Mike but then with the same cylinders times twice, same injectors, and same air ... we should double their horsepower :D

H'man:

I swapped everything you could swap - injectors, harness leads, plugs, plug wires, distributor caps, rotors, coils. It was always #7. And #7 has the same compression as the cylinders around it. So, based on that, I was thinking I have an air leak around #7 or something else leaning 7 out. Now John has raised the possibility of improper mixture and spray pattern at idle due to low fuel pressure for the injector's requirements. Why it affects number 7 more than others, may have something to do with the nearby bypass. Dunno, but since I cannot find any air leak, I'm interested in looking at Johns theory.

Hi Bill, guess I was thinking perhaps slight clogging of #7 injector or such. I have to tell you, what you describe makes little sense because behind #7 is of course #8, and it should have even less of what #7 has little of. So WTF :confused: ... guess it could be a small air leak at the injector hole? Try sealing/testing there for leaks by squirting something inocuous at the injector seat and watching to see if it drains?

He has already swapped injectors, etc.

It is a design flaw in the manifold and the way the bypass is set up. Weld a diffuser in there so all that air isn't concentrated right at #7.

That is the way I am leaning. Shouldn't #7 plug look a bit leaner when pulled, also.

Maybe if all you did was idle around, which I know from experience is next to impossible when you have so much power available with a twitch of your toe. And once you open up the throttle well the last thing you are thinking about is the lumpy idle... :D

Diffuser...hmmm...

Help me to understand HOW the bypass works. I understand that it is there to allow the boost that this type of SC generates even at idle to not get forced into the engine. Instead the air recirculates out through the bypass. It does this based on the vacuum signal from the manifold at idle. Strange that it is getting a vacuum signal if there is supposed to be boost that needs to vent. Anyway, once you jam the throttle, boost in the manifold allows the bypass valve to close.

So, air isn't really "concentrated" at the bypass tube. It's being allowed to ventilate out of the manifold via the tube. I can't quite grasp how this might affect 7, although it is certainly affecting airflow.

I thought it might be sucking the fuel mist from that area, so I took a pipe elbow and inserted it inside the bypass and pointed it towards the center of the manifold box, so the bypass would draw air from the center. Granted, this elbow could be an obstacle for airflow to cylinder 7 as well. It had no real effect positive or negative, and I have driven with it for at least 5K miles this way.

I would prefer the bypass to be more centered, but I cannot figure out exactly how it would be affecting cylinder 7, the cylinder it is closest too.

A diffuser might make sense if the air were entering from the bypass and blowing on cyl 7, but it is leaving but not entering there, correct? Even, so, my pipe elbow pointing to the center, away from cyl 7, should have helped.

BINGO..that was my next plan when i took the whole thing apart at some point.
Some sort of baffle that routes the intake of the bypass to a slightly differnt location.

Like this...

edit...or a copper pipe will do! I guess i wasted 15minutes whipping that up. :roflmao: Exact principle Bill..... :thumbup: ....and that didnt change anything?

Tony, that's essentially what I did with a copper pipe elbow. No change.

http://www.billsworkshop.com/P928S4/sc/diverter.jpg

The vacuum signal doesn't actually come from the manifold - it comes from the inlet to the SC. This inlet never sees boost because it is pre-SC. It gets vacuum when you have low-throttle deflection because the SC is sucking in air against a closed (or mostly closed) throttle body.


Has anyone taken one of those clever laser thermometer things to measure the temp of the 7th exhaust port in relation to other exhaust ports? This would give some additional info.

Bill,
Just a thought.
Try disconnecting the vacuum line to the bypass and see if there is a change. I can’t try mine at the moment.

don't do that. The bypass valve will see atmospheric pressures and be forced to close. This will cause the supercharger to cavitate and your car to be unhappy.

Hmmm...good idea. I have one but its broken. I know where i can get an other though. If i had EGTS hooked up it would be :rockon:

Er, uh, lemme check where I have the bypass vacuum source..... Mike - mine is T'd-into the manifold source that feeds the fuel pressure regulator and that is how Andy hooked it up.
It's right next to the source for the vac/boost gauge. My finger is on the T. The manifold shows proper vacuum at idle and cruising and jumps to boost when I hit it. 10K miles with no issues other than the odd idle when warm. Should I remove the T and move the bypass over to one of the throttle housing sources? I see no vac source on the SC inlet, unless I'm completelly misunderstanding how this works. Probably so.

http://www.billsworkshop.com/P928S4/sc/bypass.jpg

WHOA BILL...i dont think that is even remotely coorect!!! :icon501:

BRB with a pic of mine..but for now IIRC it loops to itself!

Heres an image from the magnusonproducts website instead.
http://www.magnusonproducts.com/images/bypass1.jpg

I know you have a different set up, but the valve looks the same?? If so, there is an open port on yours that needs to be plugged isnt there?
Wierd?..but it obviously works!! :burnout:

Mine loops to itself like the pic Tony provided.

Jeez, I don't get it. I've been driving this way since the install.
http://www.billsworkshop.com/P928S4/sc/bypass2.jpg

So how do I fix this? The valve is the same one as in your picture, Tony. BUT the port on the bypass valve is inaccessible due to the brake booster hose outlet on the SC intake right below it. And there's no nipple anyway. Can't I just grab a source from the throttle housing, although some of the throttle housing sources are rather tiny. Odd that I am the only one with this arrangement.

You are not the only one Bill! I can’t look at mine right now to check. I can’t remember where I am getting vacuum to the valve, either like you or from the throttle body. The other port on the valve is plugged. I don’t understand how the valve can work without a vacuum source. How can it get vacuum plugged into it’s self?

Daryl: The configuration that Tony shows looks like a loop, but the port is intake vacuum sampled prior to the SC and it feeds the bypass valve vacuum diaphragm that controls the rod that pulls the valve door open under vacuum. Not a true loop. Mine is drawing from the manifold AFTER the SC. Goofy. Somebody will explain it.

Well.... logic states that since the manifold is under vacuum (engine is sucking more air than the SC is putting out in a no-load, no-rpm condition), your setup should work as well. Once you open the throttle, you'll have to hit atmospheric at some point in time and the bypass will close.

I haven't seen 2 vacuum gauges side by side comparing the manifold vacuum to the inlet vacuum, but maybe this configuration causes the bypass valve to stay open slightly longer and reduce the possibility of pinging/detonation at max-load/low-rpm conditions. I know Andy had some tricks for people with tip-in issues... but i'm not sure if that's what this is or not.

The nipple that the valve is connected to samples vacuum from the inlet side of the supercharger. It is on the inlet-side of the little throttle plate.

So the port I have plugged provides vacuum to the valve? Without getting to technical. The port I have plugged creates vacuum similar to the way the throttle body creates vacuum? I’ll check my notes and emails on Monday to see what I have form Andy regarding how to install this.

I would need to see a picture to be 100% sure, but as long as the vacuum port of your black actuating valve is plugged into some source of idle vacuum (inlet or manifold), it *should* work as designed.

OK, mine has worked fine all this time, so let's move on to other issues. I have an IR gun. Won't probably have time to look at the exhuast temps during rough idle with the IR gun for a few days. Also, I ordered one of the injector test lights a few days ago.

Mike,
Just to follow up on this idea of disconnecting vacuum to the bypass valve. Do you see it being a problem just long enough to see if there is a difference at the one cylinder?

To be honest with you... I have a list of about 7-8 "dumb" things that were done on my car (some on accident, some on purpose)...

Among those things... when I first had my kit running (first 85/86 prototype), I ran without a bypass valve for a few months. It should go without saying, but it only caused issues at idle. My idle was pretty rough and the engine would "rock" somewhat in the enginebay. It also made the car "louder" than necessary. I can't quite recall, but it may have also added some difficulty when starting the car.

After I got a bypass valve and everything was sorted out... the car still made 350rwhp on 5psi (eaton/noic) with perfect air fuel ratio and good compression (except for 1 cyl that was busted before the install). The car made a 1,000 mile (roundtrip) to Devek and back and never even hiccuped.

All i'm saying is that you're prolly ok to do it for a day... or 2 :D

Hey, here's another topic....

I can't find the note now, but didn't Andy or someone else indicate that the pulleys used on the Jag/Eaton have been changed and won't work with the quick-change mount I got? What do I do for pulleys and where do I get them if I want to go up to 6 or 7 lbs.?

eaton pullies are fun... here goes...


If you have a stock jag/eaton, you can do one of 3 things:
1: Use the pulley that came with it
2: Use an upgraded cobra pulley
3: Have a pulley custom made

Regarding #2, there are a few issues:
Issue 1: The jag/eaton supercharger has a different offset than the cobra/eaton. If you use a cobra pulley, it won't fit perfectly and may or may-not cause damage in the long-run. I ran my jag/eaton SC with a cobra pulley for at least 5K miles and the SC unit didn't appear to have any issues with it.

Issue 2: Since the offsets are different, there may have been a slight issue regarding alignment of the SC pulley in relation to the crank pulley. I don't recall exactly what this issue was, but I was able to get it running with slight modifications.

Issue 3: Cobra pulleys don't get much smaller than the pulley that comes stock w/ the jag/eaton. My guess is that cobras use a large crank pulley than the 928 does. IIRC - the smallest pulley I could find made 5psi on my 85/86 (stock jag/eaton pulley is 4psi).




Now comes Andy's quick-change adapter:
Once you press the quick-change adapter onto your SC, you will essentially be using the twinscrew pullies which come in an abundant number of sizes. The only drawback is that you need to get the pullies from Andy since he has to specially modify them to work with the quick-change adapter that he designed.

Mike - thanks for the answer. I should have ordered some extra pullies from Andy I guess, unless the machining is something I can have done locally. I'll get some pullies and have a look. Thanks again.

Thanks Mike,
I was thinking for just a few minutes at idle. Long enough to pull the injector wire on the suspect cylinder. If it also causes other engine running issues then it may not help anyway.

Bill, did you mention that your engine runs great when cold? That’s the way mine is. How can I trick the computer into thinking the engine is cold? That may give us at least an idea if it’s to lean or rich as John pointed out. If it smoothes out when doing this I will check the bad cylinder and see what difference it makes when I remove the injector wire. If that corrects it I am inclined to go with the higher fuel pressure and re-chipping the computer.

Daryl & Mike:
If the theory that the culprit cylinder #6 or #7 is running lean, how about just cranking up the fuel pressure to see if the idle smooths out, as a diagnostic test. Since Daryl pointed out that this would be the "fix" he would use if this were found to be the case, you could do what we do in health care, which is what we call a "therapeutic trial". That is, "assume" the diagnosis, and test the assumption by applying the appropriate "treatment".

I fear that you are going to stumble across another health care situation in this case, however. That is something we call "untoward side effect". If you are right in your assumption of the culprit cylinder being lean, in the face of a good sampled total A/F ratio, enricheniing it by elevating the fuel pressure is going to push the rest of the systen rich, even if it feels better at idle.

I don’t know if these pictures helps with questions regarding pulleys on the Eaton SC. The first is the way my SC was shipped. The pulley was way out of alignment. The second picture shows the 8 lbs boost pulley with a piece that pushes on to the SC shaft then the pulley bolts to it. Last picture shows the extended pulley that now lines up with the crank pulley.

You will only be able to "fool" the mixture rich at idle when the car is running open loop with no O2 sensor active.

Otherwise - assuming the loop is holding the A/F at 14.7:1 then changes to the fuel pressure will be compensated for, and the loop will hold the A/F at 14.7 until you get to the point that the loop gets out of its range.

Daryl, I seem to remember that you told me you tried running open loop once ?

If I understand how the bypass works, wouldn't #7 be running rich when the bypass is open? Wouldn't it be taking air from the manifold (near #7) and sending it to before the SC where it would pass through again and be distributed to all cylinders? With all the bypass air coming from near #7, that should have less air and run rich... right?

Hi Brian,
In a previous post by John Speaks he alludes to the fact that our injectors are built to run at 43 lbs not 30 lbs as we are. He thinks the spray pattern may not be as it should in that case. I am thinking that alone could make the difference to cause this slight idle problem in an area that there may be a little turbulence caused by the bypass. Remember this is a minor problem only at idle. You might even say nit picking. Off idle I think the extra air movement corrects this. The engine runs perfectly and smoothly. Which says to me the air/fuel must be pretty good across the board. The spark plugs show this as well. In Johns post he alludes to the fact that the sharktuner can tune the existing computer to handle the increased pressure and provide the proper air/fuel at idle, cruise, and full power. That is just my gut thinking on this and I could be totally off base.
I could easily live with this and I am sure most people wouldn’t even notice but I know it’s there and would like to make it as close to perfect as possible.

In my case my fuel regulator is not adjustable.

All pre-87 L-jet and LH-jet cars run at that pressure. Most fuel injected european cars run 2.5bar or lower fuel pressure regulators. Very few run as high as the 3.8bar regulator on S4s. I doubt that's the problem.

Hi Matt and John,
I don't know if it is running rich or lean. All I can tell you is that the engine runs perfectly when it’s cold. When it warms to operating temp it starts to idle a little rougher. My thinking is if I could trick the computer into thinking the engine is cold just long enough to see if the engine idle improves. This might give us a clue as to if it is running rich or lean.

John,
Before I installed the SC my car was running in open loop. After the install it ran very rich. My a/f readings were in the 12s and low 13s across the board. It ran surprising well considering how rich it was but lacked the power I am getting today. I changed the pins so the computer would run closed loop and connected my O2 sensor to the O2 plug at the fuse panel. That’s as far as I have gone to date.

Matt,
Are you aware we are running these injectors at 30 lbs pressure? They are designed to run at 43 lbs

Brand: Ford Racing Performance Parts
Product Line: Ford Racing High Flow Fuel Injectors
Injector Advertised Flow Rate (lbs/hr): 30
Injector Advertised Flow Rate (cc/min): 309
Quantity: Sold as a set of 8.
Injector Impedance: 11-18 ohms
Driver Type: 12V saturated circuit
Overall Height (in): 3.045
Seat to Seat Height (in): 2.563
Manifold O-Ring Outside Diameter (in): 0.545
Fuel Rail O-Ring Outside Diameter (in): 0.523
Outside Diameter (in): 0.982
Injector Plug Style: Bosch/Amp Style
Wiring Harness Included: No
O-Rings Included: Yes

http://www.southfloridapulleyhq.com/index.html has an interchangeable pulley system that a machine shop should be able to machine the nose of your SC to accept. I think my Eaton SC takes a Kenny Bell pulley. A spacer had to put on the nose to bring it out far enough to line up with the crank pulley.

All Bosch injectors are specified at 3bar or 43.5psi. They are designed to run at a wide variaety of pressures, to be consistant they test the flow rates at one pressure, 3bar. All pre-87 L-jet and LH-jet 928s have 2.5bar/36psi regulators that (should) run 30psi at idle. That is normal for fuel injected cars. Porsche is odd in running pressures as high as 3.8bar/55psi. Some GM TPI engines are over 50psi, but most American and European injected engines are 3bar or less. Mustangs, Neons, and OBD I Jeeps that run the same (19 or 24lb version) Ford/Bosch injectors you are running are 32-39psi (2.7bar regulator).

BTW, if you want to test the low idle fuel pressure theory, plug the vacuum line that goes to your regulator. That will give you 36psi up until the BEGI kicks in. That's the way Kibort runs his car (although I assume he is running a 3.8bar S4 regulator). You'll have higher idle fuel pressure than the cars that use your injectors from the factory.

Throttle Cable Routing
 

Here's a picture of the piece I cobbled together to route the throttle cable.

I had a problem with the thin springy thing that Andy included. It flexed too much and my throttle had a mushy feel. I added a bracket to stiffen it by where the throttle cable stopped against the edge, and punched a hole through my hood when I closed it. :mad: Turns out that some flex was needed when the hood closed.

Fortunately, someone backed into my car a few weeks later, and the front end had to be fixed/repainted. So the hole was welded, sanded, bondoed, and painted. That was my call to arms, and I emailed Bill Ball for pics on what he had done. His had used a 2 piece setup, with one piece of aluminum coming off the throttle body, and it required the TB to be oriented such that the screw holes are parallel with the ground, which mine was not, so I came up with this:

http://forums.rennlist.com/upload/ne...able_route.jpg

Daryl:

Where did you source the pipes, elbows and hoses you used to run the cold air intake? :biggulp:

Thanks in advance,

I don't think anyone can make the statement as to what cyl7 is doing (rich or lean) until we get an infared tester on the exhaust port. As others have already stated, the spark plug from that cyl looks great.

If you're running what Andy sent you, that spacer is an adapter because a normal autorotor pulley cannot mount to an eaton. And yes, it also puts the pulley in proper relation to the crank pulley as you stated.

If you allow the begi to see atmospheric pressure, you can just use the center-screw to adjust your fuel pressure.

Try this:
Take the vac line off your begi and plug it. Now, while watching your fuel pressure, adjust the center screw. Your fuel pressure should go up/down.

MAKE SURE you remember what fuelpressure your BEGI was set at BEFORE you start tinkering so you can put it back when you're done.

Mike,
As per Andy’s instructions I am not using a BEIG. I only have the 85-86 Fuel regulator and the two dampers.
I know the engine likes what ever the computer is doing while it’s running cold. If I add more pressure than that I may not see any difference or may end up running worse.
Do you think that disconnecting the plug to the temperature sensor II would cause the computer to think it’s running cold? I want to do this just long enough to see if it makes a difference.
As soon as I can get the car back into the garage I will measure the temperature on each exhaust port to see any temperature differences. Hopefully tomorrow.

Glen, email me at daryllmiller@hotmail.com and will send you parts, pictures and instructions on what I did.

Matt, thanks for the addional info on how fuel pressure and injectors work together.

not sure about the temp sensor thing.... but try unplugging the vac line to the regulator. That might bump your pressure up a bit (by allowing the regulator to see atmospheric pressures - aka WOT)

Mike,
I'm using the intercooler, crank pulley and oil inlet from Andy's kit, the rest has been changed. I bought a remanufactured Jag Eaton M112 and a spacer was machined at the install shop. It is possible Andy designed something similar but it was not included in the kit I received.

Interesting. My 422 pulley is off by about 1/8 to 1/4". Many have seen this offset and I tried getting Andy to help me with it but he continually said no one else had the problem. Yet I now know of 3 different systems that do in fact have the problem...

Andy made a spacer/adapter which allows you to mount a modified autorotor adapter to the eaton since the eaton can't really use any other pullies (check a post i made earlier about eaton pullies).

This was considered a "stage 2" upgrade for late eaton kits. I'm pretty sure he wouldn't give it to anyone unless they specifically paid for it, and had high-octane or an intercooler available. I think he only offered this option during the last 2-3 months of selling kits.

I'm pretty sure these are completely unrelated. The jag/eaton has different offsets and pullies. From looking at Rick's pictures, he isn't using the stock jaguar 4psi pulley. His shop must have created their own adapter which appears to be similar to the setup that andy has.

Can you illustrate the alignment issue for me? I have access to another twinscrew car I can check and see if it has the problem.

Originally Posted by mspiegle
Mike,
Since I didn't buy the SC from Andy it was my responsibility to adapt it to his kit.
I don't know, not having seen an Eaton SC supplied by Andy, if my unit is identical to those the kit was designed for.

Mike are you refering to something different than the "quick-change" adapter Andy sold me? I paid extra for it. I'm just not quite sure if I need Kenne Bell pulleys or something else.

this baffles me.
Why isnt it needed?
What is your fuel pressure at max boost and what size injectors are you running?

i sure hope he see more than Atmospheric pressure at WOT? :icon501: :cheers:

BTW, Mike, thanks for stepping up and helping to explain some of this stuff and the idiosyncrasies to the guys here even though you were not selling the kit. :thumbup:
If Andy has the time to send an email to Darrien, he has time to help folks on here with the questions. I know...onward... but its BS that he can lurk and not help. very nice.

OK, I moved the vacuum source for the bypass over to the throttle housing instead of the manifold and plugged the T outlet. I dunno why but my vacuum readings at idle are higher, running 25. Used to be 18-20. The idle seems much more stable. Not 100% but improved. It's kind of cold today, so this is not a good test. Perhaps in moving the vacuum source I sealed up the intake system boots a bit better as I did have to remove the throttle housing to get to the unused (plugged) vacuum nipple underneath. The boots do require very careful placement. As everyone knows, they can seem fine but really aren't unless you get everything just right. The bypass closes as soon as you give it gas, even just a little and reduce the vacuum even partially. Wonder if it is working better this way. Don't want to make too much out of this just yet.

I believe your SC is of the same model (M112 right?). The way I understood it is that either the casing or just the snout is slightly different. For example, take an M112 from a cobra and an M112 from a jaguar and they're *almost* the same except for a few measurements.

IIRC, Andy decided to go with the jaguar model because of cost and availability.

Tony, somewhere earlier in this thread Mike mentioned that Andy spec'd no BEGI for Jag/Eaton applications running 4 PSI. I guess the OEM early fuel presssure regulator could keep up with fule flow required in that application.

Yes, the "spacer/adpater" I refer to is the same as the quick-change adapter. You should be able to use the autorotor pullies with this adapter - but they must be modified in a special way to fit the quick-change/spacer/adapter.

Andy determined at some point in time that the stock 928 fueling system (with a couple easy mods) could handle a few pounds of boost. I think if you're making under 375rwhp, you could upgrade your injectors, use 85/85 regulators, and that would be enough. Don't quote me on that though...

Talking to people about their 928s makes me feel like I still have one :D

Anyone wanna trade 2 E30 BMWs for a 928? :D

I'm sure you guys have heard it a million times, but it isn't BS... Andy is actually incredibly busy with a few things on his own plate right now... especially within the last 2-3 months.

Keep us posted!

25in of hg?! Holy crap, i've never seen that much on a 928 before.

roger that. You had to make 1 minor mod, but it works. I've seen the AFR graphs as proof.

Excellent.

If they can be modified with a hacksaw, I can probably handle it. :o

Yeah, I thought it was odd too, but the car seems very happy now, with a smoother idle.

Originally Posted by mspiegle
Mike,
Magnuson can make a snout "any" length needed. It was more cost efficient to have a spacer machined for the Jag M112 I have.

Bill,
Have you tried unplugging number seven to see any difference to the idle?

Tony,
I am running 8 lbs boost intercooed, no BIGI, only an 85-86 fuel regulator and the two dampers. I have 30 lbs pressure at idle and I don’t know what it is at full acceleration. I do know that the A/F gauge sees 12s. flat out. This how Andy told be to do it!

Quote from one of Johns posts earlier:

“The development car runs 42#injectors with a stock S4 fuel system No RRFPR or other device. It is fully mapped up to 495HP crank. That's just an example”.

Someone please tell me how to make those nice grey boxes with the quotes in side.

Ah, so you DO have a jag unit. Are you saying that you tried this with a stock jag pulley and it didn't work?

Tony,
Forgot to mention, I am using the Red Ford #30 injectors.

You must use the (QUOTE) and (/QUOTE) tags (replace parenthesis with brackets)

You can also click on the "quotes" in the lower-right hand corner of another user's post to quote his/her post.

The snout pulley sits back too far.

i'll check that and report back here

Mike,
The SC pulley didn't line up with the crank pulley. I don't remember the size specs on the pulley that is on the SC now or if it is a Jag pulley, I think it is a Kenne Bell pulley.

Mike, I have said it before and I will probably say it again, you are one helluva nice guy. And intelligent too. :cheers:

Yes, I'll second Jim's comment - Mike, you've been a GREAT help to us and Andy, and we do hope you get back into a 928 soon.

Glad to hear Andy is busy with other things. There was a time when the SC kept him from having anything else in his life, and I'm glad that has changed for his sake. I do hope he gets a chance to drop in here and contribute, but having you here makes that much less critical.

Thanks again,

I will second that, Bill, as soon as he lives up to his commitments...

Since you're not using any FMU, be careful if you test running the car without the regulator vacuum line hooked up. Not only will you not get vacuum to go lower than 36psi at idle, you won't get pressure to go above 36psi on boost.

Glad I could help on the regulator/injector understanding.

Hey Matt,
Thank you for that last bit of info. So the amount of boost the fuel reg. sees
determines the amount of pressure?

The regulator has a spring in it that sets pressure to 2.5bar/36psi. The vacuum line on the back either assists the spring (boost) to close down more increasing pressure or fights the spring (vacuum) to not allow it to close as much decreasing pressure. Whatever you're manifold pressure is relative to atmospheric, add that to 36psi and you'll have a rough idea of your fuel pressure.

Someone asked earlier what size tires I was running...
265/35/18

Also, Sab asked earlier why his and Camerons Sharks would go into limp mode occasionally and that this only happened when idling. i wonder if in some weird way this is connected to the #7 mystery?

Maybe their cars have that weird EGT system Porsche put on the later cars to prevent cat fires?

Yep, and if #7 isn't getting enough air...

Could be, but my car never went into 4-cyl mode at idle despite #7 being dead as a doornail at times and me pulling things off whatever cylinder and running it that way while testing. The system is present 89+ and changed in the GTS years (relocation of the sensors).

Here's a handy little chart i have. HTH

I wonder what the flow is at 32-36 psi?

Maybe not related at all. Regardless, it is interesting you have two cars set up at the same time that go into limp mode occasionally at idle. As I recall both are GT's?

Jim, yes, that's true, it could be relevant to them.

What do you consider limp mode... I saw this earlier and meant to respond but am unsure of the meaning "limp mode"

In the pass footwell reside the brains. You have to pull the cover on the side to see them. In later cars if the system sees that you may be dumping gas into the cats, among other things, it will shut down 1/2 the motor aka limp mode. If you look at the brains when this happens either a green or red light will be on telling you you are in limp mode. I bypassed mine at one point because i had no cats and was stranded and I thought Marc was going to blow a vein.

OK thats what I thought...

We had that issue, and we pulled the bosch relay that controls that... but yes the GTS did have that problem and was well discussed in posts a year or so ago.
Not sure if my car now with the kit running optimally would display the same issue but I think it would..

I thought that this feature requires that the engine have EGT sensors...if it does arent they only on cyls 4 and 8?
Ive got an 87 so i dont have this stuff..so im cluless really. just a thought

Bill,
I am having the same issue with rough idle after the car warms up and I want to run a theory by you: when I installed the SC, I removed my '89 idle stabilizer and attached it to the 85-86 throttle body. I know the 85-86 stabilizer is different than the '89, could this be the cause? Has anyone with an 85-86 car with the SC kit had this issue? Susan will send me an old stabilizer if she has one, and I will swap it out. Any thoughts?
Woody

Woody,

>when I installed the SC, I removed my '89 idle stabilizer and attached it to the >85-86 throttle body. I know the 85-86 stabilizer is different than the '89, >could this be the cause?

The only real difference I can tell between the 85-86 Idle Stabilizer (IAC) and the 87 and up is the diameter of the inlet/outlet ports. The 87 is larger so it can flow more air so it is doubtful changing the IAC will help with your issue.

I haven't seen the warm idle issue that some are experiancing but I am pretty positive that remapping via the SharkTuner will solve this issue with those systems that have this issue. In my opinion what is being experianced is the changing of the intake system without remapping the computers to reflect the changes. This is why I am very excited to have the SharkTuner and will make custom chips for our SC kits to optimize the computers to the intake system changes. Once I get my systems finished I will be happy to share any map files with Supermodel owners that are compatible. I will also have the SharkTuner available for rental so you can create your own cusotm maps tailored to your exact system.

I would expect more idle issues than what I have if the IAS was incorrect. The warm idle issue in my case is definitely a drop out of cyl #7. BTW, my idle is 95% better since I routed the bypass vacuum source away from the manifold and to the throttle housing instead. It no longer shakes AT ALL at stoplights when warm, and there is only modest irregularity when sitting in neutral/park, whereas 7 was basically dead before. Go figure.

I am anxious to apply the Sharktuner and see what it comes up with.

I saw a pic of Murphs intake routed into the fenderwell, this means the intake hose is about the size of the alternator cooler hose. Tim has run higher boost than any of us so I was surprised at the hose diameter. My question is what is the minimum size intake hose we can run for up to 8lbs of boost.

I am going to use a custom fan system which should give me room to run the hose into the same place on the pass side as the hose for the alternator runs on the drivers side. That is if the hose I can use there is adequate which I am guessing should be based on what Tim is doing. :burnout:

I agree with Dave Roberts regarding the Sharktuner as a valuable tool to help clean up this sort of problem. I've been experimenting with mine for a few weeks now. Although it is on a near stock S4, I can tune the idle mixture quite nicely as well as other areas of operation. You can tweak the warm up mixture compensation too. Mine was off toward the lean side which made for a bit rough running when about half warmed up. It also shows the duty cycle of the idle speed controller so that can easily be checked along with the coolant temp., injector duty cycle, and even fuel consumption per hour. The LH is a good injection controller, but it can't do everything. It will adjust mixture within +/- 20% of the base map. If you are beyond those limits, then who knows what the mixture is. I also see that the LH goes to open loop at less than WOT switch activation when under relatively high load and/or high rpm. Then you don't really know what your mixture is either. How many have dynoed their car at less than WOT to check mixture? At WOT, the LH uses the base map plus an enrichment map. When in open loop, but with the WOT switch not activated, the base map only is used. All these are settable by the Sharktuner. There is a complete set of Non-cat open loop maps available for tuning too, if you prefer to set your car for continual open loop with no O2 sensor. You do need a wide band O2 unit for tuning in all cases.

Thanks for your comments Louie ! To clarify a couple of points...

If you get to the limit of the +/-20% adjustment range possible in the map, you can reset the map to get into adjustment range by changing the injector size figure in the Parameters screen of the SharkTuner... e.g if you cannot get the mixture rich enough because you are at max rich on the map, set the injector size a few % smaller, and the SharkTuner will then automatically lengthen the pulse widths.

It is always possible to check the A/F ratio under any condition with the SharkTuner, open or closed loop, either visually or using the data logging facilty.

Louie has given us excellent feedback on the SharkTuner, and made some very useful suggestions to improve the operator interface. These are being incorporated into the next issue of software/user manual, due in the early New Year.

Many thanks Louie :-)

You are not correct about the hose diameter.........

John:
Is there a maximum duty cycle for these injectors?

Jim, the wider the better on ourtype of intakes from what ive read. the TS tend to be more sensiive to inlet restrictions to flow than the CS set ups.

As for maximum duty cycle, im pretty sure you going to be running at 100% WOT, I was with 24#lb injectors, which is why you up the fuel pressures to increase the fuel flow at that point. Im really not sure about the mapping that the LH has for this....still trying to understand when it does or doesnt go to 100%

I thought I had seen a pic of the intake hose going where the alt. hose normally does but now I can't find the pic... Need to remember to take my meds...

Tony, I am concerned for the service life of the injectors if we are exceeding design duty cycle limits. It's bad enough that we have all of those "relay, relay, relay" issues. I just want to understand whether we are tempting fate again.....

In George Suennen's car, the intake, which I helped install, routes out under the passenger side fender in a space between it and the belly pan. I think it is 3", but Gretch can correct that.

Unless you remap things, i dont think there is much you can do.
You have to remember also, youre not at 100% duty , 100% of the time....

X amout of HP requires Y amount of fuel. No two ways about it.

There is a SC car out there putting 400rwhp out with stock 19lb injectors. Its at 100% duty im sure and has to utilize pretty high fuel pressures to get fuel but its working fine as far as i know?

Louie pointed me to this program. Kind of fun to play with.....

Below is something i posted from another thread and is from an EMS book. I read in another book that Bosch strongly advises against a duty cylce over 80%. I don't think there was ever a clear cut concensus on what this all meant.

They specifically discuss the Bosch pintle injectors but not in enough detail other than to warn against 85% dc and the problem of idling with the bigger injectors.
Fuel injector expert Russ Collins says injectors can begin to fibrillate at more than 80%dc causing fuel delivery to become nonlinear in fuel delivery and causing lean out problems.

I don't know what the install looked like in george's car....his oil cooler is located differently than the 89GT. I do understand that required an alteration to Tim's design......My car has a 4" air intake routed from the drivers side fender.

It's 4", per Gretch.

Im not sure what a "pintle" on an injector is, but i think its the little protrusion that sticks out of the cap on the end, area where the fuel comes out? Dunno?
Both my 25lb and 30lb are the newer style that dont have that. just 3 or 4 small holes

With George's 90 S4, the oil cooler blocked the driver side area. I know Tim provided George with a larger hose than originally at some point. Sure could be 4 inch.

It's hard to use the same route for a TS. Tim's kit replaces the fans and the intake hose routes from the head of the Vortec at the center of the radiator straight down and then off the the passenger side (in George's case). In the case of the TS, you have to navigate the radiator hoses on the pass side and the fan shroud unless you did some oddball routing around them or changed hoses and to a DEVEK fan shroud or some other fan arrangement. I have the DEVEK fan shroud, but the path still looks obstructed by hoses. Daryl's exit out the passenger fender by moving the coil and cutting a hole is an option.

We don't need 4 inches, do we? The intake path goes down to about 3 at the throttle housing and MAF, doesn't it?

There are pintle and disc. Ours are pintle. IIRC the disc are made by Lucas? Or maybe that is just another name for them.

http://images.google.com/imgres?imgu...lr%3D%26sa%3DN

Hi Bill,

>We don't need 4 inches, do we?

I am not gonna touch that one :-)

> The intake path goes down to about 3 at the throttle housing and MAF, doesn't it?

MAF is 3.3444" (85mm) ID and 85-86 throttle body is approx 3.15" (80mm) ID.

If anyone needs one I have a custom calibrated 4" (104mm) ID 928 Super MAF.

I found out an interesting bit of LH info while working with John Speake's Sharktuner. The shop manual and all other Bosch Motronic (LH) information I've read has the injectors batch fired at once per crank revolution. The LH switches to once per every other revolution injector firing at 5100 rpm. This is to allow for more time for the injector to stay open. The Sharktuner permits changing the RPM where this change from once per rev to once per 2 revs takes place. If you were to see your duty cycle getting higher than you want at the switchover point (5100), you could alter that RPM with the Sharktuner. I have 85% in my mind as the max recommended duty cycle. I might be wrong on that and it likely depends on injector design too. The duty cycle is probably more to worry about if max duty cycle is hit on a continuous basis than momentary. If you are setting up for a land speed record attempt, be concerned. If an occasional merge on to the freeway (we know we never street race), don't worry much.

Bill,
Regarding the size of inlet pipe. There is a simple test to see if the inlet pipe is big enough. Corky Bells Supercharger book explains this. It's a matter of hooking up a vac gauge in front of the MAF. I will do this as soon as I can see some dry roads. Perhaps as eary as next week. My inlet pipe is 3 1/2" I.D.

Louis that is interesting switches at 5,100 RPM !

DR,
Is you bypass connected to the manifold at a different location that ours? I am thinking about the idle issues.

This has to be the longest most well thought out, sharing of ideas and problem solving S/C post amongest a varity of cars and S/C kits to date. I'm learning alot.

Hi Daryl,

>Is you bypass connected to the manifold at a different location that ours?
>I am thinking about the idle issues.

I have had 2 different styles of Bypass Valves mounted in 3-4 different locations and none of them affected or caused idle issues. Heck I have even done testing and dyno runs without a bypass (temporarily) and that didn't affect idle either.

I am not completely sure of where your bypass is located and routed as I have seen Andy do them a few different ways. Give me a refresher (or pic) on where/how yours is done and I can tell you if I have tested that configuration.

I am amazed at the rate of discovery and learning that is going on recently, regarding understanding the LH EFI system. A year ago we were hearing that the LH firmware was proprietary and unassailable. :typing:

Dave,

Mine is located at the back, drivers side corner of the SC, below the BEGI

https://rennlist.com/forums/attachme...chmentid=52437

DR
Best picture I can come up with right now. Someone elses install. I hope they don't mind.
I am trying to understand why one cylinder is running differently than the other seven cylinders. On my car it's number six and Bills car is number seven. When we disconnect the injector wire from that cylinder it makes very little difference to the idle speed. All other cylinders show a clear drop. We have checked every thing we can think of including swapping injectors. I would like to understand why this is happening before moving on to computer tuning. Others are complaining about idle issues but no one else has tried this cylinder drop test that I am aware of.

Hi Jim,

It looks from the photo that yours has the bolted flange on the rear plenum (pre-SC) and then plumbed into the intake "after" the intercooler. I have used this layout with no problems. Are you plumbing he vacuum line from the port on the bypass body to the vacuum actuator? If so it seems to be OK. It is my understanding that the vacuum source should come from after the SC which it picks up on the boosted side of the throttle plate on that bypass. I have tried it both ways, i.e., vacuum from after SC and pre-SC, can't tell any difference either way but I know Andy is adimate about it coming from the boosted side so it sees vacuum and boost. Honestly, I am totally sure why it needs to see boost, but I have questioned some of Andy's procedures before.. and have proven myself wrong on a few :-)

Daryl,

That photo has just solved the "cylinder 7" issue in my mind. To me it is now obvious why you guys are having issues with #7 at Idle and when not on Boost. What I think is happening is when the Bypass valve is open it is circulating air from that hole right beside of #7 and putting it back into the rear of the SC and therefore robbing air when the bypass is open (idle and off-bosst).

My locations have all been on the rear top middle of the upper Intake or on the rear backside of the lower intake, no where near a cylinder where it can suck air away from it.!!

In addition I think a pretty easy fix would be to plug that hole/port and create a new hole/port on the backside of the lower intake. Plenty of room there and should be an easy update.

Also, here is a quick easy test you can try. When you are having the warm idle problem and you see #7 is no doing anything, try unpluging the vacuum source for the bypass valve (and plug the vac supply port so to prevent a vac leak) which will close the valve. If you idle improves and/or #7 starts working better you will know this is the problem.

BTW, do not leave the bypass valve "unhooked" for any lenght of time as this could cause other problems and void your warranty.

Hi
There are several "sub threads" inside this general one, but on the subject of injector duty cycle...

Porsche/Bosch were quite clever with the post 87 engine setup. They use 19# injectors (maybe they were more available at that time), then run them at a higher fuel pressure to get the flow rating up, and then play the trick that Louie mentions where they switch from switching the injetors on/off every engine rpm to once every 2 x rpm. That way they can keep the injector on for approx 1mS longer (this is the opening time of the injector)

Even with all these tricks the injectors are actually on 100% of the time at max power, for these cars. This has been observed on Louie's car when he was testing with the SharkTuner. As he observed, a road car running at 100% will be for relatively short periods, so overall longevity probably doesn't suffer.

80% is usually taken as being a good rule to work to.

I would think a good design rule for a s/c car would be to use a large injector, so you can keep the duty cycle and max fuel pressure as low as possible. Until the Sharktuner, it wasn't possible to run 42# injectors and get a good idle unless the fuel pressure was dropped to such a low level that spray pattern and pick up response were unaccepatable. That problem is now solved.

I am not a fan of very high fuel pressures ! Some books state that the injectors cannot handle very high pressures - can't shut off properly - although evidence of such problems is hard to come by.

Regards

DR,
That would make perfect sense on cylinder number seven. In my case number seven and eight show a definite drop in RPM but number six shows very little change.
I think I am going back through the total diagnostic stages again just to be sure I haven't over looked something.

I wish others with this problem would check the rpm drop and let us know what they find.

Does higher fuel pressures not atomize the fuel better then lower pressures?

I think higher pressures DO help, but the issue is (correct me if i'm wrong) that the injector can't close the pintle quick enough (or at all) because the pressure is so high.

ford makes a 104mm throttle body and I have the 4" tubing in the garage.


How do you recalibrated it?

I wonder what gains if any would be had?

.

Yyyyyyyyyup....how cool, i was just looking at one of my data logs....heres the PROOF !

My observation is the bypass valve closes with any reduction in the vacuum, so that is why you saw no difference using the manifold or the throttle housing as a vacuum source. The default setup is to use the vacuum port on the valve itself, which is pre-SC (not boosted). Not sure why Andy blocked that off and insisted on manifold vac/boost for the valve. I now have the bypass hooked to the throttle housing vacuum and it seems fine AND my idle got much smoother coincidentally.

In the other posts you speculate that it is pretty obvious that the bypass valve location is contributing to the problem with cyl #7 that I have reported in my car. I will try the test you suggested. I have tried to divert the direction of flow by inserting an elbow inside the bypass that would gather air from the center of the manifiold, but it made little difference. Your idea to just close the valve temporarily makes more sense. Daryl - try that.

Hi Tony,

>ford makes a 104mm throttle body and I have the 4" tubing in the garage.

I have a VERY nice Billet Aluminum 4.25" Neck 95mm (1450 CFM) Throttle Body (large Ford square flange Style) in stock that mates directly with that MAF :-)

>How do you recalibrated it?

It was done by Mr. Speake personally :-)

I also have a custom MAF programmer that can calibrate any MAF to output whatever you like, you can even use twin MAFs and calibrate them to work with stock 928 computers :-)

>I wonder what gains if any would be had?

With the right Blower and boost you can bet your booty it would :-)

Any one tell you your a tease DR! :roflmao:

may be after Christmass here when i get a few thing$ $quared away.. Id have to modify my rear inlet to fit a 4inch pipe...and from there it snowballs im sure....make this fit...that fit...bend here...cut off there...grind that. But, its somehting that i had set out to try at some point. Im not even sure how restrictive the stock inlet systems for our TS are yet...I think Daryl may be looking at that soon.

The inlet i have from the fender at this point is "to the nats ass" as far as fitment for length, i might have to ditch that and do the standard 90' to the front.
:cheers:

A truly non-resitrictive intake would be one without a MAF. MAP with a linear translation to MAF voltage would be great for "you's guys"

Brendan,

>A truly non-resitrictive intake would be one without a MAF. MAP with a linear translation to MAF >voltage would be great for "you's guys"

I have one of those gadgets here also, converts MAP signals to 928 MAF signal for use on a stock LH Computer :-)

Tony,

Here are a couple of "little" 1450CFM 95mm teaser photos for you, custom made for me with provisons for 928 IAC in/out and direct bolt on 928 TPS...you should recognize the little fellar to the right :-)

How's that for "teasing" :-)

You gonna use TWO of those for the dual TB?

Hi Brendan
I don't think there are any advantages to running injectors at a higher than rated pressure. In general it is a good policy to run devices like that at the design recommendations. For injectors, pressure and duty cycle.

Regards

>You gonna use TWO of those for the dual TB?

No not on the production version, but with my latest modular design you would be able to swap to that unit easily....that particular TB is for "Big Custom Twin Screw Systems"

Dave,
What’s your thoughts on using or not using the BEIG? For example I am running an Eaton 8 lbs boost intercooled with the 85-86 fuel regulator, #30 injectors and the two dampers. This is the way Andy wanted me to go on my install. I am using a wide band A/F gauge and mixtures are in the ball park. I am running in closed loop and getting 14s at idle/ cruse and 12s full throttle. I noted on one of John’s posts that they are testing with #42 injectors and using the stock 88 fuel regulator then re chipped using the Sharktuner. I am not sure what boost they are running.

Hi Daryl,

>What’s your thoughts on using or not using the BEIG?

I prefer to not use the BEGI or other FMUs if I can tune the 928 properly without them. One reason is less "non-factory" fuel lines to potentially cause fuel leakage issues.

I am using our standard Adjustable Fuel Regulators (the newer billet style we have been selling for 3-4 years) and have had great results so far. Plus it is a direct replacement for the stock regulator so less muss and fuss as far as installation. Our Kits will also include a remote adjuster for this regulator to make it easier for fine tuning or changes in the future. I have tested both ways with and without the BEGI (and many more ways) and get better results with just our adjustable regulator. Of course as I get closer and if final testing shows better tuning using the BEGI, then it will be incorporated into our Kits. If you look closely at the side photo of my prototype you can see I have a temporary fuel return loop just at the back edge of the cover so I can install or remove the BEGI in just a minute or so for testing with and without (see pink circle in photo below).

Also, if I just needed to have additional "on boost fine tuning" it would be simple to add a bleed-off valve system to our adjustable regulators that would give it the same bleed off function the BEGI has. Doing this would give me the same features as the BEGI, but of course would not give the 3 adjustments that you can get when you combine a regulator (adjustable or sock) and a BEGI.

>For example I am running an Eaton 8 lbs boost intercooled with the 85-86 >fuel regulator, #30 injectors and the two dampers. This is the way Andy >wanted me to go on my install. I am using a wide band A/F gauge and >mixtures are in the ball park. I am running in closed loop and getting 14s at idle/ cruse and 12s full throttle.

IF you are getting proper (power and engine safety) A/F ratios then there is no need to change from what works. The only reason I could see you needing to change is if you modify your setup for more boost etc. and need to change your pressures and the adjustable regulator will give you that option without additional plumbing.

> I noted on one of John’s posts that they are testing with #42 injectors and >using the stock 88 fuel regulator then re chipped using the Sharktuner.

That is completely feasible using the SharkTuner and would be the optimum way to do things in the long run. Unfortunately that will currently only apply to 87 and up 928s so other ways need to be perfected for the other years.

Exactly what DR said. If it works, don't mess with it. There is no need to add further complication and cost to something like this unless it is necessary.

Hi Mike,
What makes you think I want to change anything?

EVERYONE wants more boost sooner or later :D

:burnout:

too true

Mike,
Ok, you have convinced me!! How high can we go with the existing compression ratio? :)

strangely, nobody has ever successfully tested the limits...

Andy was going to test the limits once. IIRC, he tried to drive his car to the dyno shop on 10psi. He had a pre-production prototype kit with a far less functional tensioner mechanism and the belt was shredded by the time he got there. He mentioned that the car was simply "insane" while he was able to drive it with boost.

I would have tested the limits myself, but a damn tree got in my way.

I think Jim H expressed interest in pushing his already powerful (465rwhp?) GT.... but he fell on his head when he unbuckled his seat belt.


The supercharging gods don't want us to have more power than we already do =(

LOL!

And I was shooting for 12psi when mine caught on fire! :eek:

SEE????

:bowdown:

Mike:

Daryl and I have been comparing set-ups, since we live relatively close together, and find that we have pretty similar systems, except for a couple of things. I was wondering if you could provide any rationale for the differences?

Running similar boost (8lb), intercooled, #30 injectors, '85-86 fuel pressure regulator, 2 dampeners.

Daryl runs Eaton compressor. I run Autorotor compressor.

Andy provoded mine with a BEGI rrfpr, but recommended against Daryl using one. Why?

Did you buy yours before Daryl bought his? Andy thought the BEGI was required for all kits (at some point in time). He actually went and tried testing without one and found out that it ran fine without it (so long as you send a boost signal to your regulators)

Brian,

>Daryl runs Eaton compressor. I run Autorotor compressor.

That is the answer, the Eaton is a 1.84L displacement ( I think) and your Autorotor is probably a 422 and is 2.2L displacment. Add the larger displacement, plus the fact the Twin Screw Autorotor will make more power than the Roots Eaton per same displacement size... SO, you need more fuel, hence the BEGI (or you could have just used an Adjustable Reg to increase pressure)!

Yes, mine was an early kit. Should I try it without the BEGI then? That would make the install MUCH easier for the firewall plumbing..........

I'm not sure what new discoveries you've made since Andy's research, but for the relatively "low" boost levels that we are running, there isn't a large difference between the autorotor and eaton (or at least that's what was determined a little while back). I think there is an easy way to figure that out.....

Brian, what rwhp numbers have both of your cars obtained? And you're both running the SAME boost, right?

My install has not been started... this consideration is in preparation for that to begin next week.

Not a TS, but I show 10 psi on the boost guage and I can attest to the insanity of it all................The car really is uncontrollable at that boost level for any more than a few seconds....if pointed in a straight line in fifth gear, I am going so fast in such a short period of time, I am terrified......

GOD, I LOVE THAT CAR..........

whoops... i must be smoking the good stuff :D

Gretch, that's what it's all about