RAD69

<center><img src="http://pictureposter.audiworld.com/24886/polishedgreddy.jpg"></center><p>I have a Greddy Type S BOV that is re-circulated, I installed it while I was trying troubleshoot a low boost issue when I determined that my Forge was not holding boost.

So long story short, I installed it and still did not get full boost. I thought that I have a another problem too, but after another pressure test last night - I am pretty convinced that the Greddy is also not holding my boost.

So I called Greddy today and they said that the Type S is only good to 18psi, maybe 20psi - if I am lucky. I told him that I need it to hold 24psi and he told me that I must get the Type R valve since it supports over 500hp. I explained that I am no where near that HP - but do run 24psi. He said another tech will call me back - but he knows I need the R. But when I do a search - I've see post on other forums where it holds 20ish and more.

Do I have a defective one? Or will this one not do the trick?

BTW - I adjusted it all the way to hard (from soft) and now I get more boost - but it flutters like a *****.

SMOKINA4TURBO

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I've had the type s on for a while now. Does the trick. I may try out the bigger valver or may just throw on another valve laying around at shop. There is pretty much no way you are exceeding the performance of that valve. Type S has larger diameter openings=vents pressure faster then oem and many other valves out there.

Try plugging the valve or you may even try removing the vacume line.

Audi2ptzero

If you make that valve too stiff you will end up not open it enough while at low vacuum and the pressure will hit the compressor wheel. This is why I went to a EVO valve which should hold 25+ psi.

RAD69

When I first got the valve, I hooked up one of those vacum testers to the vac line on the BOV. I tried to see how much vacum it will hold, but it did not hold any vacum. I could not pump the tester fast enough to compensate for the vacum it was losing.

I tried a similar test on both a Forge and a Bailey and they both held vacum. My theory is that the diaphram is leaking and consequently there is not as much boost as there should be to push the piston shut.

To my knowledge, the spring is actually the differential between the boost in the intake and the boost on the otherside of the diaphram that keeps the piston shut. The spring should not be doing all the work... Maybe mine is?

RAD69

I adjusted it in order to help prove my theory that it is leaking...

and yeah, it only flutters when I let off the throttle.

BigDog

to lessen the spring pressure to eliminate the flutter. Hopefully Yippers will chime in and enlighten you with his experiences.

RAD69

I like boost.

Audi2ptzero

The spring should not do all the work since it is just there to put the valve back to a closed state at a set vacuum.

RAD69

that is what I think too.

Yippers®

You don't want to run that valve with it all the way in for long. That 'flutter' at lift you hear will hammer the compressor ...

I hold over 20psi without issue. Sounds to me like tehre is something amiss with that particular valve.