Hey guys, i am new to the WRX, and turbo'd cars in general... Last week i was test driving a 2004 wrx, and i noticed the turbo spooling was audible. It was a distinct whistle. There was no distinct "blow-off" from a BOV, but just a whistle. Is this something that is normal on the wrx stock, or is it some type of modification?

 

At higher RPM range 4k+ on WOT you will hear almost nothing but the high pitch "Spool" sound.

At lower rpm it shouldn't be audible on a stock wrx, but removing the silencer/elbow, and going catless or TBE (Turbo back exhaust) will definetly change that.

As for the BOV, the WRX BOV is a 100% recirculation valve which throws the access air back into the intake, which is noticably quieter than a 100% atmosphere BOV. You will still be able to hear it with said mods, but while stock it should stay a quiet, but semi-audible "woosh" sound.

 

oooo ok... so basically what ur saying is what I was hearing was all stock. And yeah, I didnt hear anything except for when i started creeping into the 4000 rpm range like you said...

 

Glad I could help