'Acoustic valve' one way valve, which way round?

[GrumpyTwig]

This may be one for Mr Fox but I do hate to pester him


The vacuum feed from the inlet manifold to the (solenoid?) / acoustic valve has a small one way valve in it, round with one side black and the other white/semi-transparent.

Should it be black closest to the manifold or white?

I may have answered my own question with the below as it appears black closest to the manifold end, is that right? Should it be allowing air only to travel towards the manifold or away?


(the thing 1/4 in and 1/4 up from the bottom left, white and just next to the throttle body)

 

[Foxspeed]

yes - vacuum pull from manifold side only - as it "sucks" the valve open!

 

[Ryan197cup]

It sucks the valve closed, it should be open on tickover and close as you drive to keep the noise down until you boot it which sucks the diaphragm closed and then the spring in the acoustic valve opens the butterfly to let maximum air down the inlet, clever stuff eh

 

[ryan197]

the valve works on suction, but is controlled via electrical signal through the solenoid, open on tick over, closed low revs, opens at 4,000 rpm and above

 

[Ryan197cup]

Yeah that's right it's only closed so you can't hear the induction noise while town driving etc, iv removed mine from the butterfly and fitted a blanking pin in the pipe to keep it running smooth and sounding sexy haha!

 

[ryan197]

I pulled mine off the solenoid n put a cable tied a bolt in the end, and a fitted a cold air feed from the valve to the lower grill, maxium cold air all the time

 

[Foxspeed]

It sucks the valve closed, it should be open on tickover and close as you drive to keep the noise down until you boot it which sucks the diaphragm closed and then the spring in the acoustic valve opens the butterfly to let maximum air down the inlet, clever stuff eh

yes it does my bad! was thinking more on the actual vacuum control valve...

 

[GrumpyTwig]

I turned the one way valve the other way round ( the wrong way ) so it was in effect not working. Didn't notice any difference tbh :\