Ok I just sold my HKS bov kit off my RX7 to my friend who has a 91 VR-4. I fit it to where his stock bov piping is and we went for a test ride. It sounded nothing like an HKS bov, but almost exactly like his stock one vented, just the regular pshhhuuu sound. Any idea to what this could be. I think he is still gonna buy it anyway just cause it looks cool and I gave it to him for 125, but I don't think he will be really satisfied without it.

 

I assume that all necessary nipples/fittings have the appropriate hoses on them? If you're in doubt (and this is my generic attempt, cos I don't have this BOV, just the stocker), maybe try swapping hoses that are of the same size just in case you've got them on the wrong places.

If you know they're on the right places, it's possible, maybe, that his car doesn't produce the same amount of vacuum/boost ours do and that could affect the sound/volume of the BOV.

my $.02

 

what are his mod's ?? that bov needs pressure to make the good noise they made. maybe he had to raise the boost up and see if sound's better.

 

yeah his only mod is a stillen dp that i installed, stock boost and I am sure that they are the right hoses because it still blows off as normal just not the right sound. Could be the vaccumm thing though

 

booooooost...................... :-)

 

booooooost = pressure = sound.........

 

Possibly the pressure screw on the back of the BOV needs to be tightened or loosened.

 

I know a guy who runs an HKS SSQV and its not all that loud on a TurboII. They run about ~6PSI stock for the S4's.

However, one of my friend drives a WRX with the SSQV and those things run 14.5PSI stock and its LOUD.