I have a greddy type s that came installed on my car (hate it). When I'm cruising at highway speeds and the throttle is at like 10-15% (like pretty low), I get this annoying whistle coming from my blow off valve. The tone changes based on my throttle position. When I'm off the throttle, it goes away. When I get passed that certain point, it goes away...but I'm concerned its not set up properly.

Should I just try adjusting it "harder"? I was never really sure how adjusting these worked...

Before some one says it...yes, I know I should get a 9 bov.

 

Mine used to do that and the prob was the spring was all rusted so it wouldn't squeak and whistle.. Is it holding boost?

 

It seems to be holding boost fine

 

Mine did the same thing, I adjusted it a bit tighter and it almost went away, still a little bit sometimes but not nearly as much.

 

What your boost gauge when it happens. Is it around 0?

 

Having the same exact problem with an OG synapse BOV, could it just be the adjustment?

 

Greddy valves are notorious for leaking.. Cranking down the spring tension may fix that but then it may cause surging

 

I'll give it a try, can't hurt i guess. I really dislike pretty much everything about this blow off valve hahaha...

Would a retune be completely necessary if i swapped out my bov for a different one? Obviously decremented, but would it hurt if i didn't?

Yea 0 or a little bit below.