Originally Posted by rv7

The stock BPV is the best "BOV" that you can run on the STi. Don't waste your money on a BOV unless you need one (i.e. you are running lots of boost and your stock BPV won't hold). They make your car run worse (unless you get tuned for it.) If you want to hear the "cool" noise, simply hack your intake silencer. Again, a BOV on an STi will do nothing other than make some noise and make your car run rich between shifts. I'm surprised that nobody has said this yet. A classic example of "If it ain't broke, 'fix' it till it is."