I am looking for the most responsive blow off valve (not the one that sounds the best). Any information would help and I would like to know the blow off valves that don't lose boost at really high psi's. Thanks a lot,
Craig

 

The stock BOV supposedly works just fine. As far as upgrades go, I believe the Apexi Twin Chamber is one of the best as far as mechanical application goes.

 

The stock one is fast because the diaphram in it is light . The drawback is that it opens at 4in vacuum,so it is open when you are idleing .If you change the spring so it opens above idle vacuum then you will not be wasting that air going out of the valve at idle .The spring my mechanic uses opens at 17 in of vacuum . So it is closed at idle (with street port ) and opens at higher vacuum when you close the throttle at higher rpm .Why spend money if you do not need to .

 

Tial BOV is the best for the money...

 

Hey Craig....may want to let people know you are running a T78 Single Turbo with a Race Ported Motor.....

I am a Greddy fan...they are simple and efficient with very few problems....Type S for under 17psi and Type R if you plan on running over 17psi.

 

HKS SS BOV. Much better spring design than the apexi, although the apex is a close 2nd.

 

TurboXS

we have run up to 37 psi with no problems on our wrx