Sab

I thought the Mercedes C class has a clutch on the SC as well.

DR

That is correct.

Warren928

Mspiegle,

I also have an 86.5 with a supermodel kit awaiting install, and it seems that our year may need a piggy back computer to run at the proper air to fuel ratio? I have two kits now, one whipple intercooled and one eaton non-IC'd. I will be using the Whipple at 9psi and an X-pipe. For what its worth I thought that if I asked you how you setup your fuel system and SMPT 6 it would save me alot of headaches in trying to get a proper mixture throughout the powerband. I noticed your AF and dyno charts (their impressive) and I thought you might be able to fill me in on how you got to that point?

People are talking about rising rate fuel regulators & problems with them, dampers, pumps, injectors, piggyback computers, other misc fuel parts, and I wondered what would be the most cost effective components for my setup?

Also, do you know if the groupo is supposed to come with gaskets to the heads and block?

I beleive that is my biggest concern: proper fuel system mixture ratios and the safety of the fuel system, and so far the rest of the install seems like it requires some thought, but this area seems to need the most attention.

Rick Carter

Warren,
I will be tuning my 85 with an M112 Eaton using an ARRFR (different brand than others are using as I'm using different fuel rails AN fittings etc. so it may not be the same for you) and the SMT-6. I will post my results and settings when all is done.

Shane

This is from when my 928 was running the whipple at 7psi, 24# injectors and stock engine and fuel management with the BEGI for tuning.

mspiegle

With respect to fueling on an 86.5, I don't think it is at any disadvantage as compared to an S4. As you can see from Shane's very nice AFR curve - the 86.5 fuel system with pressure-adding device worked very well.

I personally used an SMT6 because I wanted to learn more about engine management, i'm **** about small stuff, I had it left over from a MAF-conversion project on a BMW, and I wanted to try to squeeze out some more performance by tuning ignition. I pretty much suceeded in what I aimed to do. I even ended up advancing the ignition timing somewhat past 4k rpms (which kept my torque curve from falling off).

In your situation, I would get the kit running first and tuned with the RRFPR. If you feel that you still need finer control over your fuel curve, then you should go for the SMT6. Also, the SMT6 can't give you more fuel past 100% duty cycle (only higher fuel pressure or a larger injector can do that). At 9PSI, I think you're going to need an RRFPR and 30# injectors at the least. Using just an SMT6 and 30# injectors (without RRFPR) is borderline in my mind. If you wanted to get larger injectors, you would end up remapping most of the LH fuel delivery via the SMT6 and you might run into small 'imperfections'

Also... there is 1 thing to note. If you plan to run the SMT6 with ignition... it will never work perfectly. There are 2 methods to hook it up. One method causes slight missing through the rpm range (the method I used). The other method introduces cranking delays when starting your car.

Warren928

Shane,

thats a pretty good ratio, holding near an ideal AF level; is the initial spike in air / fuel to 16 from something? Or maybe their all like that before winding up to speed, it seemed to come into line at 3400 rpm. When your ready, let me know on the ETA for the package.

Mspiegle,

Thanks for the reply. I will try what you said.

What gaskets do I need to attach the manifold to the block and heads? Maybe someone can direct me to an older post, thanks!

Shane

No that is Tip-in-leaness from when the engine passes through atmospheric and into boost. Once I understood how to tune with the BEGI I was able to make that go away as well.

mspiegle

whoops, sorry. I forgot to answer that. Andy does supply gaskets for use with his kits. You *could* make your own if you were in a pinch, but his are cut via water-jet (i think) and are pretty accurate. I would see if you can get ahold of Andy's

DR

Mike,
>I would see if you can get ahold of Andy's

If you can't I have the template and gasket material here and can make Warren a set. Actually this sounds familiar and I think Warren sent me an e-mail about this a while back and it is possible I forgot to reply. Warren, if that is the case I apologize, even thou I have been a "little" distracted that is still no excuse.

Cameron

Gents,

Mine is a '91 GT with the Andy Keel Jag/Eaton 112 running the 6.7 psi pulley (generates a tick over 6 psi of boost on the GT). If I was to be AFR tuning my blown GT this weekend with, oh let's just say a SharkTuner, would you consider the following to be the ideal goal?

14.7 : 1 at idle
14 : 1 at cruise
13 to 13.5 : 1 at WOT low to mid rpm
12.5 to 13.0:1 at WOT at high rpm (say over 4500 rpm)

All opinions and your rationale are welcome. Oh, and please answer by Friday!!!

Edit: I have stock cats.

Thanks,

mspiegle

The general answer to that is to aim for whatever gives you the most power without any sign of pinging or elevated exhaust gas temps.

I would start with 11.5 at WOT below 4K. Above 4K, you could try raising it to 12.0. I personally would never run higher than 12.5 on a boosted shark unless you could tune in some ignition retard.

Your idle/cruise AFRs look good, but the O2 loop will try to enforce that anyways.

Did you ever try the coding plug trick to pull out some timing? Also, what octane do you have?

Cameron

I run 93 octane. I will have the aussie coding plug (coming this week) which provides for a 3 degree retard in timing in mid to high rpm ranges. I should have included that as part of the baseline.

Why so rich at WOT below 4K?

Th Dude

You can forget about trying to get in touch with Andy. He is back to practicing his "ostrich technique" again...head in the sand.

mspiegle

I don't consider 11.5 that rich, especially for 91 octane. Its a safe AFR for a boosted car. Anything under 11 I would consider rich. Like I said, all you need to do is find the point where you get the most power, least exhaust temp, and no pinging. Since you have 93 octane, you can probably try aiming closer to 12.0.

You also probably don't need an aussie coding plug. There is a good chance that all you need to do is solder 1 wire into the plug (takes less than 20 mins to do), and you've got an aussie coding plug. When you're done with that, you can cut/remove the wire to go back to normal.