umm at the time i didn't have a bov installed on the car, just the factory bypass valve. if you knew a thing or two about turbos, you'd know that it's definitely not a bov making that sound. it's kind of like when you talk into a fan, your voice sounds all weird. that's basically what's happening with your turbo, the air is being forced back into the compressor's spinning blades causing the noise. it sure is a sweet sound but bad for turbos over a long period of time, that's why i run an hks ssqv now

^wat the owner said