lol seriouslyChrisco said:well... *sighs*
yes you have to be under boost before you let off the throttle in order to get the "sweet bov sound."
the reason it is called a blow off valve is because it is venting the pressurized air back out of the system by "blowing" it off, or in a sense, purging. This is to negate the effect of compressor surge. Not just to sound cool.
Actually it's not boost that opens it. It's vacuum that opens itTaSe said:Trubo needs to spool to create boost to push the valve open to Vent when the gas is released. Low RPM you might get lucky you might not. My cousin as a HKS SSQV on his SRT4. He pushes 16 PSi n he's BOV doesn't open at lower RPMs n he gets compressor surge like a mofo. I had a HKS on my 7M with stock 6lb's and it opened up at low rpms. Not by much but still vented.