Well my friend he just bought a used hks bov for his wrx. Well he came over and i didnt hear anything when he down shift.

So i poped open his hood trying to adjust that little 10 inch screw in the middle of his bov. Told him to drive it, still didnt hear nothing. I played around with that adjustment screw, still nothing...


What u guys think it can be? Some help with be nice..