I'm having some boost issues right now. My mods are as follows. T25 setup on USDM 9.5:1 motor. JWT C1 cams. JWT ECU. 2.5" downpipe. 2.5" cat with pipe through it. 3" mandrel bend cat-back exhaust. 370CC injectors. Stock MAF.

One day my car was working perfect at 9 psi. The next, it only boosts to 5 psi max. It feels kind of choked up. It will only boost to 5 psi in any gear. It is not the boost gauge reading wrong. Any thoughts?

Check the shaft for play and wobble. Could be a turbo going out.


-Kris

There's barely any noticeable shaft play. Also, when i put in compressed air into the compressor intlet using a pressure leak tester like the DSM guys use, I only get around 1 psi at the boost gauge. Any help?

TTT

didnt you say you could hear it leaking?

i think it is the compressor housing seal :(

THink I can just buy a new compressor housing seal? Oh wait, once I take it apart, I gotta get it rebalanced, might as well get it rebuilt. Crap. I need to try an air compressor.

i believe you can get the compressor housing off without taking the shaft out, negating the need for a rebuild/balancing.

have to ask biggie about that one though

you should be able to pull the compressor housing off without needing to rebalance it.... check for leaks with an air compresssor if you get access to one.

Hope that helps a bit

I was checking for leaks with an air compressor. Also, it doesn't help when I can't hear out of my right ear. I've had an ear infection the last few days. But that helps if I can remove the compressor.

Ok, so I pulled the wastegate line and it continues to boost and boost and boost till I let off so it's not the turbo or my piping. It's the damn wastegate actuator. Is the actuator arm adjustable?

HA! TOLD YOU!!

sooo, uhhhh, i think the actuator spring is fucked up, too soft, making more boost unpossible. its the only thing it could, anything else would cause more boost, not less.

Nah, I think the arm is loose. That's why there seems to be slow buildup of boost. It feels sluggish. Initial boost response should be snappy and quick with the T25. There is a preload on the wastegate from the arm to keep it closed. I think this initial tension is gone because the arm is loose. That's why before, with a more choked up exhaust, the boost would be jumpy. It woulnd't build any boost then jump.