ak47bravo

Hey guys, got my FM II tuned today (link ecu) and I was wondering if anyone knew about the GFB BOV that FM uses. Can I turn it from hard to soft? If I can do you know where the screw is located? It doesn't sound like just a whoosh sound. It is more of about 3 or 4 sounds. I have heard from some ppl that there is a style of BOV that does in fact sound like that, and that it isn't compressor surge. Can someone help me with this?

Brentikus405

I had the GFB on my Mazdaspeed for a few months. Yes you can adjust the spring tension; the vac line fitting has a retainer nut on it. You can loosen or tighten it. FWIW, my GFB never vented fully in sub 10 pound boost. I did experience a decent amount of compressor surge (sounded like a chug-chug-woosh). I have had the HKS SSQV now for almost a year w/out any half-vent problems.

Brent

ak47bravo

thx ima go fiddle with it