Ian964

My car was modded by the PO and it has a K29 turbo. It turns out that the cat is still on the car and was "choking" the larger turbo. The mechanic said that this was causing pressure to build up because it couldn't get rid of the air fast enough.

So I am having the k29 rebuilt and I also got the cat removed. Its being replace with a B&B twin tip muffler.

Hopefully with the working turbo and the free flowing exhaust I'll see some more performance.

Vince964T

That was interesting.
What will they do with the turbo ?

Vince964T

Did you have performance loss ?

Mine is not smoking after a turbo swap (and WUR rebuild) to a K27/29 Hybrid but power is down. Dynoed 2x at just below 300HP.

Wondering if I may be have the same problem as you have with to much cat back pressure. My cat probably took a beating when the WUR failed causing the mixture to become very rich.

I have enough fuel (have not seen the air/fuel ratio myself), good CO values, car runs great, boost is as it should be at 0,9b revs normaly just low on power :-(

Ian964

Vince964T: This is what I was told. I'm not the most mechanically inclined when it comes to working on the car, so take it for what its worth.

When the turbo blows, the seals go and it starts to blow oil. The cat is right down stream from the turbo, and in my case, the cat filled up with a ton of oil sludge/cake and became very restrictive. I replaced the cat with a B&B twin tip muffler so its much more free flowing now. My mechanic thinks that with my mods, B&B headers, 1 bar spring, k29, B&B Muffler, the car should make in the high 300's. We'll see when I get it back in 2 weeks.

Vince964T

Cheers
Went to the track yesterday and the car is not lacking much, still keeps up with GT3s in a sttraight line but it used to be a little bit faster and now it's with a bigger turbo. Can't be a big thing, not much missing perf wise.