BlownV8

If your car's ECU can only handle x psi of.boost, why not just put in an adjustable popoff valve so it can't spike the boost. It's a shame you can't get the ECU to cooperate.

LaserSVT

I love this car more than anything I had prior but I have never had a car that was so hard to modify in my life. I have been modding cars for over 20 years and helped to break ground on a lot of tuning on the new Mustangs and new Corvettes but this thing is a whole different level of PITA. lol

Dr Matt

What turbo's are you using? Sounds like what I'm going to want on my Fairmont once the 427" Windsor is ready.

LaserSVT

They are Borg Warner Indy turbos.

BlownV8

What are the specs on the turbos?

LaserSVT

Never really looked them up. Just look up Borg Warner Indy turbos. They are the turbos Indy cars use.

ItalianJoe1

Probably something in the EFR series, but there are many sizes like any other turbo line.

The EFR is a fantastically efficent turbo, they do spool very well and make huge power for their size category. Had good luck with them on the cobalt platforms i've tuned, they always impress me. 500whp from a stock 2.0L engine on 29psi is nothing to sneeze at.

RaceHorse

I wonder if the blowoff was further away from the intake it would be more effective. Is it safe to say the quick spool turbo pressurizes the intercoolers and air goes right into the intake (drawing in air) before blowing out the blowoff valve which requires the pressure to hit a certain point to open?

BlownV8

Blowoff valve is typically vacuum operated while a pop off valve is pressure actuated. Maybe an electronic programmable waste gate would be best since it could eliminate boost at the source.

RaceHorse

Don't the speedriven intercoolers have the tial blowoff valves mounted in the front? So there is a delay waiting for vacuum activation. The stockers on the turbo may aid in less spikes being further from the intake was my guess.

AMG-Driver

@Laser

You can also scan the throttle body opening via OBD2 in %, I think it is more a calculated percentage value, but maybe this helps. At least in my old SLK32 I could see it via OBD2.

Honestly, 124 MPH with constant 18 PSI up to redline shows that there is still a lot to test with the car.

If your car was in Germany, i could give you a helpful contact to sort out the gremlins in the ECU. For example a Canadian Customer shipped his E63 BT to Germany to make complete 5,8 Stroker built and the car is already shipping back to CN.

LaserSVT

Thats not how a BOV works. You are thinking wastegate which is on the turbo which is what controls boost pressure.

The car already has a stand alone electronic boost control that works well EXCEPT when the intercoolers freeze.

Car does need more tuning though. Its a good second slower than it should be.

RaceHorse

Gotcha blowoff for the excess air after throttle body starts to close. So your boost control can't operate the waste gates quick enough and causes the spike?

LaserSVT

Apparently. Its much faster than the stock computer but these turbos spool so fast and with that super dense cold air it just couldnt command the gate to open fast enough.

BlownV8

A popoff valve will fill the void. I can't imagine how fast the car would be if you did an aftermarket ECU.

StarvingArtist

I can't imagine how fast it is now. sigh.

Welwynnick

Laser

Maybe a stupid question, but does your car have the throttle body gasket mod?

Nick

LaserSVT

I havent a clue. Never heard of it so I would assume not. What is this mod?

Welwynnick

The M275 engine has a small TB gasket for some reason - smaller than the inside diameter. It sticks out a few mm into the airflow.

You can replace it with the M137 TB gasket, which is 8mm larger, and fits the port. It might make a significant difference on your engine.

https://mbworld.org/forums/cl55-amg-...striction.html

Nick

LaserSVT

Very Interesting. Thank you. Matt, did you end up gaining anything with the change?

Dr Matt

Not that I noticed at the track, but hey, it's the cheapest & easiest mod I ever did to my CL so it has to be worth it. Lol. Might make no difference at all, but somehow I feel better with such a stupid restriction eliminated.

StarvingArtist

I'm having withdrawal symptoms, any more news, pics, video, stories, burnouts? I think it's going to be another year or two before my v12 days begin.

LaserSVT

Car was dropped off with Adam and Andy at Eurocharged in Round Rock on Tuesday. Car has been to the track twice. Only could squeeze an 11.4 out of it. Andy got to see it run and after speaking with him and Jerry they have some ideas. Have to keep the car from going into limp mode and have to get some more power out of it. Should be a 10 second car and its not quite there yet. Hope to have it back soon.

1ForcedBenz

Hopefully they'll get you where the car needs to be. For references sake. Mine and I know some others have run 11.5s stock in the w215 65's & basically Tune only w215 65s are in the 10's.

And my w216 65 with all the BS I've gotten done to it has never gotten me below a 10.94, and that seemed like an anomaly in dyno mode for the run. So I'd say your supported into the low 10's with all that hardware. But yet again "car meet wall" as far as the tuning goes. Hope there able to get around your limp mode. I know I had fought that myself and that's where my story still is. Even if it doesn't go into hard limp, my w216 cuts power and its noticeably softer even without the full power cut.

I wonder does your car do what mine does, it will roll on boost when rolling into the throttle then it feels like it bleeds some power "boost" down then somewhat rolls back in? As in does it not really come to this massive boost spike where it should be blowing the tires off at any speed if the ECU did nanny the power?

LaserSVT

Yup. Its like bobbing on an ocean, pull hard, pull, pull hard, pull, pull hard....okay im done pulling.