Blow Off Valve
 

I'm am a newbie to turbos. Just picked up a Mazdspeed 6 today. I was watching a few videos on youtube and saw some ms6's with really nice sounding bovs. You can't hear the stock one at all if there is one?

Is the bov a direct swapppable part or are there other things you have to do to change one. From what I saw I really like the way the HKS SSQ v2 sounds.