GregBBRD

I've got a supercharged 6.0 liter engine here. Has a Vortech Supercharger with a Vortech water to air intercooler. Apparently makes about 19 pounds of boost....I have no idea....I'm literally afraid to go out and drive it...much less step on it.

The engine has S4 intake with S3 computers. Appears that the S3 wiring loom was used and modified to fit to the S4 intake. Has a "great big blue" fuel pressure regulator.

Has 30 pound injectors with an Autothority performance chips.

It would literally barely idle when I first got it.....it had virtually no vacuum to the fuel pressure regulator. All of the vacuum diaphragms that were designed to see only vacuum were blown, apparently from boost. Got all of that fixed and now it idles...but obviously very rich.

Uses fuel like a 747 on takeoff from LAX.

The very first thing I did was change the oil.....stunk of fuel.

The car seems to run (at cruise) under 210 degrees. If you shut it off....after about 5 minutes it starts puking out coolant, from the overflow tank....but the radiator has a leaky tank and I assume that the pressure drops and the fluid boils.

Or are the head gaskets already screwed up?

Got all my "Sharktuner 1", with the ability to tune the '85/'86 brains and finally got my computer to recognize the system.....that took several days.

First obvious problem is that the Sharktuner system did not recognize what "map" was being used. There were cursors in both the full throttle map and the cruise map.

Turns out that the throttle switch is hooked up to the idle stabilizer leads (at the brain) and the idle stabilizer leads are hooked up to the idle switch leads (at the brain).

Obvious questions:

How the hell did this thing drive here?

What is it going to take to fix it?

I'm smart enough to know the only reason there is a head gaskets (if they are still "alive") and pistons still in this engine is because there is lots of fuel "covering up" the obscene amounts of ignition timing.

Obviously, I can redo the stupid wiring problem....and get an idle, cruise, and full throttle map working. However.....there is still not going to be any boost ignition timing retard capacity and it would seem, to me, that as soon as I start removing some of the huge volumes of fuel being delivered, this is going to be an issue.....

Apparently, John Speake makes an EZK box with a map sensor, so that the brain can detect boost and then make changes in timing, when under boost.
Is this what people are using....or are they (you) just running stock timing, at boost.......and praying?

Imo000

Stock timing, runs a bit on the rich side for safety but mine is only 6psi. I think most of the others higher boost setups have timing retardation built into the map. I'm not aware anyone running a proper boost related ignition retarding system but maybe there are a few that do.

ptuomov

S3 computers -> Porken would probably know a couple of hacks

However, I'll say this: If the car still has the hot-wire mass air flow sensor, then it's going to be tunable for boost just fine. Other than some temperature effects impacting the knock threshold, the engine is not going to care how the air mass got into the cylinder, just how much of it got into the cylinder. One just has to pull timing at the higher load rows in the ignition timing table, those rows that a normally aspirated version of the same engine never could visit.

(Now, if you're splitting hairs, you'd probably want to also add a small dependency on the charge air temperature as in input to the ignition timeing, but that's about the last 5% and sounds like this car is not 95% there as is.)

One thing that you _don't_ want to let it do is to use the WOT switch to trigger the WOT ignition map in S4 EZK. That's a vector (function of only rpm, and not load and rpm) so it doesn't know whether you're flooring it under boost or without boost. I know nothing about S3, but in S4 you can either cut the WOT switch line to EZK or use Sharktuner to disable the feature (or both, if you like both the belt and the suspenders).

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The stock Porsche fuel pressure regulators and fuel dampers in my experience work well with boost, never heard of a problem with those.

PorKen

That sounds like a hot mess.
How well does the S4 manifold fit on S3 heads? Flappy deleted?

The long duration S3 cams are surprisingly knock adverse.

Knock sensor(s) would be a good idea, though.
FYI, I saw a knock light to replace the NLA KnockLite - Gizmo K-Lite


Switch to EZK and LH2.3?
Personally, I like EZ-F and LH2.2 better for tuning.


A 2-bar modded EZ-F would be a good starting point.
A boost pressure switch for WOT would be good, too.

There is a LH2.2 map which determines when the LH goes open loop at MAF vs. RPM, but the LH2.2 WOT addition is only triggered by the WOT switch.

Iwanna928

A 6.0L with 19lbs of boost would max out 30lbs inj quick. I would think you would need much bigger ones and a new tune to go with it. You are a 928 genious and I am a retard but my Thunderbird SC needed to go to 57lbs injectors on my little 3.8 as the 36lbs inj were maxed out at 19lbs.

Don't know if that could be a issue but it caught my attention. With the money that is tied up in that engine and overall setup I would think he would get a eng mgt. system that is current with a big IC.

Good luck!

There is a guy named Dave Dalke that is a Supercharger, building, modding/tuning genious.

email is mdkracing@windstream.net He might be able to help.

Ketchmi

I am running a stock 89' 5.0 (with thicker .074 cometic headgaskets) using 42# injectors and the Super FMU with a 7-1 disk. At 15.5psi it turns 630rwhp with an auto. I don't pull any ignition at all and experience no knocks while maintaining a 12.5/1 afr at full boost. Granted, that's at 4400' altitude which does help a bit. BTW, this is being revamped due to 120ish psi fuel pressure at full boost. I built this one before the availability of a sharktuner. It actually idles great at just under 30psi static with 42# injectors.

I'm willing to bet that you are nowhere near 19psi as I am running the largest counter rotating straight outlet Vortech they make (V7Ysi) on this setup and it's maxed out at 15.5psi on a lowly 5.0 (once again at this altitude). I doubt that it is using the V7Ysi as I had to do a lot of "relocating" to fit this one. Let me know what model Vortech you are using, the pulley size and if you can find the disk size in the "great big blue" regulator (probably a Vortech Super FMU) and I can give you some help making it right.

A properly tuned 6.0 at 19psi should theoretically be in excess of 800rwhp, a nice ride for sure. I'm maxing out an 044 pump at these levels so the fuel system would have to be even more stout.

GregBBRD

Thanks for the ideas.

ptuomov

+ on the 044 pump. Bigger injectors allow one to run the 044 to higher hp. Less fuel pressure required.

I am running two 044s currently in the car, second coming online above 5000 rpm on boost.

GregBBRD

Good information. I have no idea how much boost it makes.....only have information from owner. I've only ran it below 3,300 rpms, to date. Too much stuff wrong to even think about stepping on it hard.

GregBBRD

We did figure out, this afternoon, that someone had simply "swapped" the two connectors for the throttle switch and the idle control valve. I forgot that the idle control valve on an S3 had a three wire connector. With the S4 manifold and the S3 harness, both of those connectors had to be extended....so pretty easy to "swap" them.

Wonder how long it has been running with this "minor" swap?

Imo000

MSD makes a Boost Retard system that I used to use on other V8s. Haven't tried yet to graft it onto the 928 yet because it has been holding up ok but this is something you might want to look into it. It pulls timing depending where the adjustment **** is set. It can be manually adjusted from the cockpit to go from 0 - 5 degrees of timing per punds of boost. I think it's called MSD6BTM. They probably have a newer more advanced model by now.

GregBBRD

Good idea, good point. No idea on what it has, currently, for a pump.

My current "budget" is too small for changes like that.....but I will take a look, for grins, before I go step on it hard.....and add that to a "future" list.

I'm thinking I should get the radiator to not leak, first?

GregBBRD

I'll send an email to John and see if what he has done for boost retard is for S4 or S3.

Way easier to use the stock wired S3 stuff, if possible.

BC

So you are saying it's an s4 engine with s3 lh computers.

If you still have the fuel that was in leeroy you can use that to at least run the car safely - it won't detonate while you fix other things. Lol

BC

There is a new 044 for sale on a truck forum I was reading today. 120 bucks.