chawkins2001

this is how my intake looks on the inside:

JoeNobody

For exhaust turbulence, could you bolt on some PLM or Renntech shorty headers, and see if that helps? No fabricate needed since they're a direct swap for the factory logs.

chawkins2001

Heard back from Tial, they said 3076HTA turbo's is what I have.

cij911

I think those are rather small for a 800 + whp car and you would likely need to be running a ton more boost than you have tried so far...

From memory, your EGTs were getting high and you were running too rich...any chance the breakup you are experiencing is from the car dumping fuel (which could drive your EGTs way up) ?

chawkins2001

yes sir, the ecu was dumping a ton of fuel on the top end.

e55amgrocket

I think you have it backwards. More fuel (rich) will lower EGT's. Less fuel (lean) would raise the EGT's.

e55amgrocket

What's the timing at when the EGT's go up? Timing is really what has the most effect on your EGT's. I think your having several problems compound into each other. Turbo's are on the small side, manifolds suck for a turbo style installation and you may also be having ignition problems that are from the other 2. You might also find out after getting your other problems figured out that the stock style intake manifold is holding you back.

cij911

Actually your statement is a common misconception...You are correct if you're running too lean you can see high EGTs, but often folks think they are "safe" running uber rich (e.g. 9:1)....Here is a good read : http://www.jpitech.com/press_releases/Bush_Article.pdf

or just google EGT and running rich

My guess is the fuel dumping was triggered by something (not sure what since I don't have the tune) and that caused the EGTs to jump. My guess is if you can get the root cause of fueling issue identified, you will easily be able to surpass 700+ whp.

e55amgrocket

He's not runnin that rich from what he said to the point that it's dumping raw fuel. That's the reason I asked about the timing because timing has a much more important part of EGT's than it being rich or lean. That article might be right for airplanes running at altitude (lower oxygen) but I've seen first hand that even running stupid rich won't cause EGT's to sky rocket. Been there and done that.

cij911

Agreed on timing, but I doubt his tuner would have the timing maps messed up...

The only thing I can think of is either : (a) the manifold is not designed properly or (b) the aftermarket fuel setup is not cooperating with the ECU fuel logic (and dumping fuel) ....My guess is (b) and the the break-up is not a result of turbulence or back-pressure, but too much fuel killing the power....

Worth the wait

IT'S NOT THE TURBOS

rockthemullet

The 3076HTA is rated for 57-59 lb/min, so 114-118 lb/min for two. Rule of thumb puts that at 1083-1239 crank hp capability, depending on system efficiency. Using the low end, and a very conservative drivetrain loss assumption (0.82), you're sitting at 888whp worst case scenario. He's got plenty of room from that 53x whp.

Joncl

Yep, as it has been said it never was the turbos. You will blow that motor before you reach 800hp

jmb614

Did you mention that your EGT's were around 1100-1200F? I wasn't aware that was on the high side, I thought anywhere between 1000-1200F was optimal? Unless of course you are talking about celcius?

cij911

I thought he was talking Celcius....if he is just at 1000 F then that is not high ....

Also important is the location of the EGT probe, if it is too far from the exhaust ports then obviously the real EGTs are higher...Most turbo builders put the EGT probe after the turbo, which sometimes can give artificially low readings...

chawkins2001

The timing at 5500rpms is right at 10* Steve. Tony tried moving it up to 14-15* and made zero change. The problem was there before we did the return style setup when it was losing fuel pressure like crazy. We did the return style setup, played with the fpr at different pressure and it made no difference.

My EGTS were 600* F in the manifolds and at least 1000* F in the downpipes. My A/f is some what steady through the pull around 11.5 but when it breaks up, it drops almost vertical into the 10's and then Tony pulls out.

cij911

Well EGTs don't appear bad (I thought you were talking C)...Not sure how the fuel maps are built in the MB ECU, many OEMs use a load based matrix.

Have you been able to run to redline at low boost levels (e.g. 8psi) ? And then slowly increase ? Have you been able to do a run @ 13 psi ?

I am wondering if there is logic in the ECU associated with the MAP sensor that is causing the an alternative fuel map to be called or dumping fuel ...

rockthemullet

That ECU is PISSED. Log the electronic bypass as a secondary TPS and tell me what it does through the pull. A power graph by rpm with that data overlaid would be ideal. You can text me if you'd prefer

turbo97se

Read all the other suspicions, now this sounds like a real possibility. If the ECU is unhappy (too much boost too fast possibly) and tries to open bypass to reduce boost and it doesn't see a reduction, it may try to back off by other means. It'd be nice if it were possible to hook this up to wastegate to see if it were true. How is the bypass currently being dealt with?

Roverron

this is what i was getting at earlier.
isnt there a way to code out the bypass flap
I remember someone else on the forum doing it

BI-Performance

The bypass is just sitting in the engine bay hooked up electronically. the butterly section is open to the atmosphere and is moving obviously as the car boosts.

Eric, Tony is going to hook that up and do a pull.

turbo97se

You can probably look at it and tell. If it is wide open when it starts falling on its face, that may well be your issue.

If you can't code it out, that will be an issue. You may need to boost clamp and add fuel controller (additional injector in boost pipe) to get you through this as a workaround.

If you are more adventurous, it may be possible to piggyback an AEM or other Standalone. I did this on Lexus IS300 allowing the stock ECU to control all functions (including drive by wire throttle) and the "standalone" controlling fuel and timing. No messing with CAN then. Not sure if the Mercedes stock ECU would be smart enough to tell if injectors and coils were disconnected. None of the cars I did this on had issues.

chiromikey

^^^THIS!!!

This should have been attempted YEARS ago, turbos or not!

sk8erjosh09

I'm pretty sure I have what you're looking for if you want everything functional on a stock ECU except the bypass valve. . .

Like I said earlier, if you wanted to run that direction to just let me know. I have no way to test without consequence, but you do...

Hulk

Chiro said it, if a piggyback were available it would be much much easier to tune these cars, unfortunately the mb ecu is a fickle wh0re and will not cooperate