My friend is having a prototype turbo system put on a 2001 Celica GT automatic. It's basically done, however it boosts to about 7psi during a shift, and only during a shift, then it goes back to 0psi.

The fuel system is fine, it's reading pretty much rich all the way through. He has a Tial wastegate, a Garret T3/T04E, 270 injectors (will upgrade to 310's), S-AFC, and that's about all the important stuff.

No hoses popped off or anything either. What could it be?

Thanks guys.

 

there should be no real loss of boost during a shift in a slushbox, maybe his tqconverter has some really bad shifts programmed. must be the the computer taking out all the fuel in a shift ???

 

It's actually the opposite kinda. It only boosts when it's shifting. No boost when he's driving in gear. He also said the A/F gauge shows rich everywhere.

 

 

possible that the gasket is blown out between the turbo and manifold, or its wastegate related.

 

sounds like oversized turbo. when it gets to upper rpm, it spools, then when u enter the next gear, not enough exhaust backpressure and it falls flat. oversized turbine wheel i should say...

just a guess.

 

yeh with a auto u need a small turbine housing

 

Are you hearing a BOV? Are you sure you have the wastegate hooked up right? It sounds like the wastegate opens under 0psi and closes under vacuum. Recheck your wastegate and BOV connections.


Randy

 

I agree. Did anyone bother reading compressor maps and actually matching a turbo for that motor?
Also what size on the turbine is he using? Sounds too big to me....oh yeah and auto turbo cars need smaller turbos too.

 

problem solved... i talked to the kid, and the problem dealt with a faulty vacume hose.