I was wondering why my HKS SSQV BOV doesn't sound the same it was before. Before I had built my motor (B18c1), the sound was very loud with a mid-high pitch tone. After the motor was built, the comp ratio was lowered from 10.0:1 to 9.0:1. Ever since I've been boosting (DRAG Gen 3) on this rebuilt block (going on 2 years now), the BOV sound doesn't sound so hot. It's nothing but a high-pitched faint tone regardless of how i adjust it. I understand people often claim the c-clamp/o-ring gasket isn't a good seal for the flange, would that be a factor? Not sure if it'll do much, but I ordered the purple-fin insert which HKS claims it'll give the BOV a lower tone..anyone already have this on?

Thanks in advance

 

I have the purple fin on right now. Its more suttle sounding, almost Greddy Type R like. More wooshing at low boost. At higher boost or more sustained boost its piercing but not like the original fin.

 

Thanks for the insight. I would think not many people would get that insert, nor it would help. Anyone else care to figure this out?