I'm running a garrett T3/T4 turbo @ 9 lb.'s of boost with a Greddy Type RS blow off valve and it seems that no matter where the screw is set at on the bov I can't hear it at all. All I hear is the fluttering of my wastegate... Is there any reason for this or has anyone ran into this problem before?

Edit: Probably should have posted this in the Forced Induction forum, I'm just so used to going to this forum I posted here automatically. A mod can move it if they want.