you should be able to keep the factory in place with the blitz and still be loud as hell. i always had my stock work in conjunction with the hks when i had stock turbos. how do you have the blitz hooked up? it must be hooked up wrong or something if you dont hear it. do you have a line going from the nipple(pressure source) on the blitz going and T-ing into the factory bov pressure source line?Troy said:I have the blitz ss and I can't hear anything. Do I have to unhook my factory BOV?