Boost Drop

[SpoolinGSX]

I just finished installing a Dejon Tool upper IC pipe + throttle body elbow with a hks ssqv bov. at full throttle it will boost to 15 then pretty much instantly drop down to about 12 and hold steady. i torqued all the hose clamps down real well and i dont have the torque specs for the throttle body elbow bolts and nuts( if someone could tell me that would be great). so im wondering why the boost is dropping. also im not sure if this is related but i boosted hard and the plastic hose attached to my boost gauge popped out of its T-fitting on the vaccum line, maybe it wasnt all the way in and it was leaking. anyways if anyone could help me out it would be much appreciated.

 

[forcedfedgsx]

ive got a similiar problem but i have a stock exhaust with a 16g so i think i am just gettin too much backpressure, in your case im not sure but stock turbo's dont put out too much boost at high rpms, a friend of mine's stock turbo would hit a brick wall on the freeway.

 

[flytalon93]

A good buddy of mine owns a 95 GST and the same thing happen to him. The vacuum line going to his boost gauge popped off, but all it needed was a zip tie around the line and nipple behind the guage. I suggest to zip tie at the T-fitting to ensure it doesn't pop off again. As far as you boost dropping, sounds like you are spiking. Do you have a boost leak tester? If not there is faq on how to build one. Try to find any more boost leaks, you will be surprised where these things are at.

Good Luck
Steve

 

[kpt4321]

Originally posted by forcedfedgsx
ive got a similiar problem but i have a stock exhaust with a 16g so i think i am just gettin too much backpressure

I would like to know how you think "too much backpressure" has anything to do with a boost problem like this.

It sounds like spike to me too, since it's not holding 15 psi, and it's dropping to 12 almost instantly. Pressure test your car, to make sure that none of the hoses for the MBC are leaking.