Hi Guys,

Just wondering if someone could explain about the Boost restrictor plastic T-pipe.
I have a Impreza Turbo 1997 Catalunya. A while ago I broke the original T-pipe trying to clean the boost pipes. So I went and bought a new one from the dealer. On inspection it looked a little different and slighly bigger. I fitted it anyway. Car seems to run a little different.. Turbo comes in later and holds boost all the way to rev limiter. It did feel not as quick so I reset the ECU and it started flying again. Thinking I might have got the wrong restrictor pipe I then went back to the dealer and get another one. This time it looked identical to the original one. Fitted it and car does not feel as quick again !!!
What is going on !!!! Do I need to do another ECU Reset ??

Cheers

Gary.

 

I'm guessing...the T-piece leads to the boost control solenoid? So, the amount of air that can be bled away from the wastegate actuator is dependant on how restrictive the T-piece is (inter alia), right? The less restrictive it is, the more air can be bled away, the higher the boost the car can run (for same duticycle)...but I would have thought that the target boost would be set to within the boost range that can be obtained with the OE T-piece...

Just a wild guess, as I said...

 

See "Decat Boost Spike Fix Idea" thread. The super long one with 15+ (and growing) pages.