Hi all, my brother has recently had the clutch replaced on his TT. Before this was done, it was boosting to just under 1 Bar. After having the clutch done, it is now boosting between 7-9 psi. The ecu is giving code 55. The car does feel down on power compared to before. I have a Mkiv Supra N/A and can out accelerate him. On paper his car should waste mine (220bhp vs 300bhp+) WTF is going on ?

Could be loads of things but look for what was disturbed during the clutch change. Maybe the intake boost pipe clips were slackened when they tilted the engine to drop the box and not re tightened. A slack clip or loose connection on just one of the boost pipes could be enough to loose the extra boost pressure when the pressure gets past 7psi.

 

Also are you basing boost level on the stock guage or an aftermarket one. Showing 7-9 on the stock guage could mean safety boost because of some other cause - bad temp sensor connection etc

 

9.5psi is normal for a stock car. 14psi / 1 bar you had before suggests either modified / boost jets or over reading stock guage

The car has a HKS boost gauge which is showing the same drop as the standard one, will check all hoses ect, thanks for the reply