PM for you, Mark

S

 

My Dad just completed this mod about a week ago (2/04). Euro TB, Runners, Plenum and "U". He said there are gains. How much? Not sure, because he has not been on a dyno yet, but he does have baseline dyno numbers prior to his headers and euro intake. So we will see.

I told him about this thread (and the whole euro intake thing) this past November and without personally reading a single word of it, and still has not, he was SET on trying it. lol, especially after the mention of a possible 20+ HP gain.

He is not on the internet at all so I rellay information to and from him. He will be sending me a small write up on exactly what he did as well as some pictures (I have a few of them now). Hopefully within the next few day or week we will have everything together and I will post the info here.

He does have a digital camera so if anyone needs pictures of something I don't show feel free to ask.

-Cardomain page is HERE

EDIT: Its an 82 US.

 

great. looking forward to seeing the results.
Scot will be dynoing his 928 soon as well, after we have fixed the fuel issues with the RRFR and the clamp off of the other stock regulator.

was in the 213hp range, but very lean. hoping for 220hp at the rears or more.
Mk

 

I have a project for someone if they want it.

We travelled down this line last year too.... Euro throttle bodies are
harder than heck to find.... so we learned how to take a 5.0 liter throttle body (pretty common) and modify the linkages back to the 4.5 Liter setup.

We have that process down and we can make a 100mm throttle body for the CIS cars out of later throttle bodies without too much trouble.

BUT - we never have been able to install it and test it for its own gain without a bunch of other mods too. We need dyno numbers to confirm the change to a larger throttle body only.

To make it work - we welded a matching diameter aluminum ring to the underside of the early intake plenum and began to cut out the old sealing ring from within it. That is where the project stopped.

Out of time what with Supercharger kits, race car preparation, and the development of GT1 fender flares for the 2004 season. Too busy.

Here is a picture of the two throttle bodies involved BEFORE we make our mods to the 5.0 liter body to make the linkages match:

http://forums.rennlist.com/upload/comparetb.jpg

<b> Here is what you would end up with:</b>
You would have a 100 mm throttle body that would bolt-on to your CIS intake shoe without mods. The vacuum lines are a little different and it'd take a little think to figure out which ones to plug and which ones to use.
On the intake plenum, you would have a stock CIS plenum with the Euro sized throttle body hole in the bottom to match your new throttle body.
The 8 individual ports to the intake runners (and of course, your intake runners) would still all be stock sized.

According to our calculations - there would be a nice HP gain with this easy swap to a 4.5 liter US CIS car. But we never finished it so I cannot say.

I'll GIVE these parts to somebody who promises to finish it, install it <i>without any other mods</i> and post the dyno results. If it works as planned, we were going to offer modified 100mm throttle bodies to everybody in our coatalog.

Any takers?

 

I can post "assometer" results

 

Ok, my Dad took his car to get tuned by the Porsche guy he knows. The very next day the guy called and told my Dad something along the lines of 'the AFM is too restrictive and he is not getting much out of the mod' (Maybe he didnt want to say your getting nothing or very little??).

My Dad did say there was some gains, but not anything significant so thats why he figured it just needed to be tuned to take more advantage of what was done...

He now wants a MAF on his 82.

Where can he get something to convert the MAF signal to what the L-Jet is expecting? Specific parts and or part numbers would be helpful.

I did search the 928 forum about this topic and it, the AFM, does seem to be a known restriction in the intake, but I did not see any hard solutions as far as converting to a MAF or otherwise...

OT:He got the car back Monday from being tuned, changed his (dead) 3 Speed transmission out for a, what seems to be Euro, 4 speed transmission. He now puts down about 15ft of rubber from a stop. . This is probably the only thing distracting him from completely being dissapointed in this Euro intake mod thats supposed to have given 20+ HP.

EDIT: Before euro stuff and headers his baseline dyno was in the 170s. (Done at 928 OC Frenzy 7 meet)

Thanx for any help guys.

 

Thanx for the link, also found THIS one while searching. Used MAF, as you suggested, instead of AFM and got better results from the search.

 

Sorry to hear that your dad had the same results as me. Do you have dyno sheets available? I'd be interested in seeing them.

 

jon, we found some subtle differences in your install, one that sticks out, is the stock plennum and throttle body that you are using. that is a HUGE diff . (and i dont think you have headers either, but i could be wrong) dont believe ***-o-meters. (unless it is dramtic, and maybe you are using a stop watch, 60-100mph.)
NOW, keep also in mind, ive got 293hp AT THE WHEELS, using a stock AFM!!

So, this doesnt mean that the AFM is not restrictive, as it is, but it can work just fine compared to a MAF system, and from what ive seen, is worth about only 10 hp. (ie same 5 liter, euro set ups, with either CIS or MAF, only put down 295 to 300 at the wheels. (only change is fuel metering!)

The Stock AFM and that air box is a very efficient system. have you seen the restrictors on ALMS panos and GT3RS's??? they are quite small, but never under estimate an inlet with a bell mouth configuration. as small as the US AFM is, its not much smaller than the small throttle body.

Scots 928 is going to the dyno tomorrow!!!!!!!!!!!!!!!!!!!!!!!!!
we did gain some good hp, based on 60-100 times and wheel to wheel drag racing. Now, with the eRAM we did gain 10 solid ftlbs of torque, and the fuel was aweful. so, we fixed the alternator issue and got the new fuel regulator on with our "clamp off" other stock regulator techique.

Ill keep you all posted.

Mark

 

I find it very hard to believe that just the throttle body and runners will yield 40 + HP.

 

actually, i got 43hp. but, part of that was the cam. NO OTHER CHANGES!!!
so, even if the cam was 20hp, thats 20hp for the intake. (make up the proportions you want. my car was an often dynoed car, fuel curves were predictable and consistant, and it was dynoed 10 times after the mods to verify. if you got no gains, look at the runners, plennum, and especially the TB. the euro TB is HUGE!! . did you use the euro runners and plennum???? this is a key area as well.

MK

Joe fan got 100hp!! for his mod. (of course it was the CF intake)

think of the throttle body of the US , being at 1/2 throttle compared to the euro throttle body.

mk



keep in mind

 

I have an A/F meter installed in my car (see my posts earlier in this thread), but I also have mixture information from my dyno runs. The mixture ranges from 13.5 (from 2500-4500) and richens from there to about 12.9 at 6000.

 

Hi guys, I know this is an old thread with lots of you been there and done that sort of thing.
I have the ROW 4.5L engine M28/10 and am in the process of collecting the 'S' engine M28. 11/12 intake to go on the 4.5L. It's also a K-Jet, so no electrics.
Most of this thread seems to be pointed at the US L-Jet version engines and not K-Jet, so I dont see any posts about the gains to a K-Jet engine.
I beleive that this mod will work for the 4.5L. How much I'm not sure but I know my engine is out of breath at 5300RPM. Shortening the runners and giving it the larger throttle & plenum without a cam change should increase it's breething somewhat.
So any updates with this mod at all??

Cheers,
Glenn
'81 928 M28/10 4.5L (10:1 comp, 3 speed auto, 2.73:1 final drive)

 

From post #276:



Start with exahust, then cams / heads.

 

I agree with Hacker. I have a US 4.5L ('79) which also used to hit a wall around 5000 r.p.m. Opening up the exhaust made a big difference - not so much in peak power or torque (I doubt I gained more than 10-15 hp) but the character of the motor sure changed. It lost a bit of torque off the line but the car pulls hard to the redline now. Way more sporty.