Originally Posted by eighty8design
Dont get a BOV for just sound..BOV is for adding power.. personally synchronic is my favourite because it is the has the best response to manifold pressure and comes to use right when you hit that throttle where other conventional BOVs take a second or two to respond!!
For performance, it's best to keep the factory bypass valve that recirculates the air back into the intake rather than venting it out the BOV.
I only have a BOV because my factory valve was getting old and started to leak. That said... SSQV ftw... it makes many sounds depending on the psi. Less than 1psi, it sounds like someone blowing through a straw. 1-5psi, it sounds like opening a fresh 2L bottle of pop. 5-10psi and it starts to make that whistling sound that everyone is familiar with. At 16+psi, it sounds like a venting bus.
It's a tad loud in the MR2 because it's a car that doesn't have the sound absorbant material under the hood. It's got many open vents surrounding the motor and the BOV's right by your ear on the other side of the firewall. I've heard the SSQV in many different cars and they don't sound anywhere near as loud as the MR2 at the same PSI.