I have a sensible oem dump valve question
 

I say sensible because most questions are about how much noise they can make! I would like mine to be silent!!

I would like to know what the noise is that I can here on part throttle. I know what the dump valve sounds like when lifting off as my induction kit makes it sound like it is a VTA valve, but it seems to be venting on part thottle. Is this right? If so I would assume the vacuum from the manifold is enough to open the valve.

I am wondering if the oem version is strong enough to cope with 17.5 psi that I run on my MY98 WRX Saloon. I would imagine that it will hold the pressure other wise I wouldn't get it, but why the early venting?

Thanks for any replies