Dakynz

After a hard downshift, blow off valve, bov has what sounds to be an issue. Bov when activated sounds stuck open.

any ideas on what the first things to look for? I’ve reached up and the butterfly valve on bov can be hand turned super easy. When driving when bov activated the sound level has doubled. And the sound is loud air at bov. Car still pulls but when you let off the air intake at bov sound level is so loud sounds as if something is up.

going to put it on the jacks. Would be great if anyone knows what this is.

anybody have issues related to bov like this?

helga203

My experience was wot started to hear bov opening . It was the diaphragm.

RGHIIZ06

Questions not trying to bash.... BOV or the red race valve? Operation is complete opposite.

Dakynz

believe these are the same thing. The big red race valve is an upgraded bov that is larger. On the p1sc you get a smaller black bypass valve

helga203

RGHIIZ06

What I was getting at is operation, the surge valve should open when your off throttle or on light throttle and should sound loud with large volume of air pushing out. It will be trying to release all the pressure built-up. This valve does not open under load aka reaching certain pressure like a BOV. I can't explain the difference in sound.

You could test it by starting it jacked up, you should have air coming out, have someone give it heavy throttle and it should close.... or use a manual vacuum pump to test open vs close rate...

helga203

That also happened to me vacuum leak. That's what opens the valve to release air. Check the hose going to the bov . If it's not that bad bov there is nothing else to check.,

Dakynz

Ok, found the culprit.

That large air whooshing sound from the blow off valve (bov). Found the reason. Where bov tubing turns to go vertical

RGHIIZ06

Ha! That's a relief, glad it was something simple.