BOV sound

[smp3000]

I'm not sure if this has been discussed before, but I noticed on the greddy type S valve that on the top it had a bolt to adjust something, I'm guessing the sound. One way said "harder" and one way said "softer".

the same bolt exists on my FM valve. Is this to adjust the sound or something completely different?

 

[TurboZX3]

I have one on my Focus. It is to adjust the pressure at which the valve opens. Set it too tight and it won't open under lower boost pressures. It should be set hard enough to hold boost without leaking and should be soft enough open during a part throttle shift (low boost).

Turn it to soft most of the way. Keep adjusting harder until you hear compressor surge. Then back it off 180 degrees. It worked fine for me.

 

[slowyellowp5]

I don't know if I'd be able to recognize the sound of compressor surge, what does it sound like?

 

[chdesign]

Hey slowyellowp5 i just noticed something in your sig that you might want to know a RRFPR and FMU are the same thing.

 

[slowyellowp5]

I was under the impression that they did the same job but one was in fuel line the other is custon made for your block

am i wrong? if so i feel like (nuts)

 

[TurboZX3]

I don't know if I'd be able to recognize the sound of compressor surge, what does it sound like?

It is a unique sound. When you close the throttle body, a pressure surge bounces between the throttle plate and the compressor wheel. It kind of sounds like a high pitched giggle with about 4-7 cycles per second for about 1-1.5sec depending on the boost level and whether or not the BOV is functioning at all.