I got hold of a second hand spec-r dump valve recently and have just tried it on my sapphire.

The car is fitted with a twin piston motorsport developements one at the mo but thought I'd try a diaphragm one to see if I prefered the noise.

When the spec-r one is fitted and the car is idling the dump valve leaks a tiny bit of air...
The diaphragm isn't split so I was thinking maybe the spring in it is not heavy duty enough??

Anyone running one of these?

Cheers Paul

 

Is your vacuum gauge reading the same as b4

 

I don't have a vaccine gauge fitted.

The leaking air is from the boost hose side not the vacuum side.

Idles fine, I think I just need to take it on th road and try it out....

Cheers Paul

 

is it leaking from the valve itself or from where it goes into the boost pipe?

 

The valve itself.
But only on idle it appears....
Once you Rev it up there's no air leak until you let off the throttle and it dumps its air (as normal)

Cheers Paul