Audi S2 700hp becomes 900+ ?!

[PRY4SNO]

Great build, thanks for sharing!

What crank did you use to get 2.5L displacement, the 92.8 or 95.5?

[Night_Spirit]

I had seen cylinder heads where the oil wasn't able to flow back into the sump. That would explain why thinner oil made the issue better.
But than the hydraulic lifters maybe got too much oil?
Head gasket with limiting bore for the oil supply was used (most engines have this element there - unfortunately I'm not a 5 banger junkie).
Or changed engine position? Angle of the block?

Hi. I think this problem can be solved. Need to make this system,but only in
crankcase . All holes in cylinder head cover ( engine breather) should be cut off and blocked.

[S2SE]

Great build, thanks for sharing!

What crank did you use to get 2.5L displacement, the 92.8 or 95.5?

Thanks!
Actually I dont know the stroke on it but the engineblock and the crank is taken from a Volvo V70 D5252T engine.

[S2SE]

Sooooooo
Last wednesday I had the car tuned in the dyno. Everything worked perfectly until Per who tuned it couldnt pass 2.5 bars of boost. It just didnt happen. So his conclusion was a too tight exhaustsystem.
I have 3,5" downpipe with 3" after that through one fullflow silencer. It made 810hp by then and Im not satisfied

The goal is, and has always been, 900hp in the engine and now Im going to rebuild the exhaust and see what happens!
Im going to strap the car up again as soon as the exhaust is finished.

[Thuppu]

I know a 1000+hp UrS with 3" exhaust end piping. But, great outcome anyway. What is that turbo?

[S2SE]

Yeah I know, it shouldnt be a problem. Perhaps the shape of it is the problem. Anyway Im going to rebuild the exhaust and make a hole in the DP so we can measure the pressure in it.

This is a comparison, 3" vs 3.5". The 3.5 is much trickier to build in the S2 if I dont want it straight out the hood:

[diesel des]

Yes measure back pressure before you make a new system. Maybe the wastgate was blowing open?

[AndyP]

Thanks!
Actually I dont know the stroke on it but the engineblock and the crank is taken from a Volvo V70 D5252T engine.

That would be the same as the AAT/AEL engine so 95.5mm stroke.

[S2SE]

Here is the curve from the dyno run by the way

[Night_Spirit]

Here is the curve from the dyno run by the way

Nice! Video?

[Acki]

Intake or inter cooler can also cause a pressure drop. Curve looks not like an turbo running on the limit (constant power curve).

[mushasho!]

Here is the curve from the dyno run by the way

Is this with CatCams installed?

[S2SE]

Yes this was with the catcams installed.
I know the intake could be a problem as well but Im going to rebuild the exhaust and go back to Trollspeed to see if it made any difference. If not then Im going to take the airfilter away, and then again I will take the tube from turbo to airfilter away to see if it makes any difference. Ive heard that the tube Im using between turbo and filter can cause turbulence.

Anyway, I have to change the airfilter since I had an accident with it:



And here's a clip from the 810 pull:

https://www.youtube.com/watch?v=PHEwYy8npDg

[Nick320]

Great project.

[blackS2]

..... Maybe the wastgate was blowing open?

thats my opinion too... we had a similar issue could not go above 3.2 bar... fixing the wastegate was the solution... (3,7bar) diameter of the exhaust should not be a problem...