C2 Turbo

Thinking about dynoeing my C2 Turbo mainly from AFR point of view,any tips ? When i dynoed my Supra TT i had to reset the ECU,switched off the traction and made a pull in the 4th gear so any piece of advice regarding the C2 Turbo ?
Another question is,if AFR is not good ( lean/rich ) what exactly would i need to do ? Can the appropriate change be made once the car is off the dyno ?
Thanks

Sameer

Yasir,
What mods do you have? With the basic mods like 1 bar spring, exhaust, headers, filter, you might wanna just increaee your CO between 3-4% just to play safe and if your still running lean, you might wanna modify your fuel distributor with Stephen at Imagine Auto to flow more fuel or just buy the Andial fuel enrichment.

C2 Turbo

Sameer,
1 bar boost spring,headers and exhaust.Any way i think i might just use some 104 oct for safety reasons when i dyno the car.We'll see in few weeks,however what numbers should i expect,330 rwhp ?

Sameer

Yasir,
You should see around 360-380fwhp at 1 bar with your mods with all others running correctly. Off course you have to get it dynoed correctly.

Miles965uk

hey if you mod the fuel head (like mine) will this automatically increase the Co2? what im trying to understand what happens here- my mechanic took my Co2 down to try and pass it through the emissions. so if at idle a mod fuel head vs stock with the same Co2 reading will it then still provide the same amount of fuel as its mechanical? so if you mod the fuel head what the difference between just upping the Co2? sorry i would just like to understand what happens. and sorry to hijack the thread! im actually want to get it on the rollers soon too
:Cheers:

scudnik

I think Sameer is right on the money with his estimate... My 89 Turbo had a K27, 1 bar spring and aftermarket muffler (no headers) and dyno'd at 309 RWHP, which is approx 365 FWHP (assuming a 15% loss).

cobalt

I believe it is actually closer to an 18% loss.

Geoffrey

I have measured a G50/50 trans in an 89 turbo to be a 15% drivetrain loss when compared on a DTS engine dyno against a Dynapack chassis dyno. Obviously there is room for error and different dynos may give you different numbers. I use 15% in my calculations as a rough estimated of FWHP for all G50 trans engines.

cobalt

I was going off the info provided by Rick DeMan who says he did extensive testing regarding these trannys and insisted it was closer to 18%. Although as you say that is based on his findings based on his Dynapack. Is there anything about the G50/52 that would cause it to be higher?

Sameer

Just curious, whats the difference between the G50/50 and the G50/52?

Geoffrey

The differences between the G50/50 and G50/52 are that the 52's mainshaft is larger and stronger, it has a larger LSD, the LSD is a 20/100 locking and the 50's is a 40/40 locking. My test was an engine that had a known value from an engine dyno, then retested on Rick's Dynapack. It is hard to go by Porsche's published HP numbers and a chassis dyno result because we know Porsche underrates their cars, and they all tend to be slightly different.

Also, if the test had been done on a Superflow engine dyno and a Dyno Dynamics dyno, the numbers might be different as well.

Sameer

Geoffrey,
Thanks. Sure do learn a lot from you guys.

maverick

We are haveing a Dyno day in Houston this Saturday. The shop has a Dynojet. My '91 has a 1 bar spring, BB headers Techart muffler no cats light weight flywheel. I will let you know what she does.

maverick

Well a hot and steamy Dyno day! Ambient temperature was 90 deg F. The relative humidity was around 75%. We did three pulls with the last one aided by a fan and some cool water sprayed into the intercooler before the run. She ran a 308 RWHP with 328lbft torque. A stock 3.6 ran after mine and posted 315 RWHP with 331lbft torque. So with 15% loss for drive train etc it was 354 FWHP vs the 300cc larger 3.6 at 362 FWHP. Given a temperature of 42deg and matching dew point he estimated I would see a 40hp+ gain so @ 400FWHP.

Buckeye19

Maverick, do you have the dyno plots from your car? I would be curious to see what the air/fuel curves look like with the mods that you have.