Originally posted by 360Guy
A BOV that has a vent shaped like a horn, for example will be very loud. I have friend that has two on his Corvette and the venting portion is round with four holes in it. It produces more of whish sound.
Those were probably the Tial that Craig was talking about. Definately the best sounding BOV's out there.
Even if you recirc the blow-off you will get somewhat of a noise depending on the maker. Bosch bypass valves sound like a quiet sneeze, very similar to the BOV noises from Grand Tourismo 3. Many cars won't run correctly unless you recirc the BOV (some MAF cars are cranky with BOV's venting to atmosphere), so this may be something to take into consideration.