any one with suggestions my car is a 2000 si greddy turbo kit running 7psi my question is this. my bov valve has more of a bottle rocket sound im looking for more of a deeper souinding one. this probably sounds stupid but someone in here prolly knows what im talking about...... my bov valve is a greddy type s

 

check out some clips of cars with a tial.

 

the greddy type rs is a direct bolt on with a much different sound, i think more towards what you are looking for.

 

The RFL and Tial bov's are more of a loud 'ppsssshhh' than any whistle like a type-s when at low flow/low psi. You'd be best off with the RS since it bolts right on and will give you some sounds besides just rushing air.