blow off valve size

How big is the actual valved opening for a popular aftermarket universal type blow off valve eg. HKS? Not the inlet or trumpet BS, but the actual size of the opening at its smallest, like 1-1.5 inches, or is it puny like .250 EGR type valve? I got a valve off a V6 300ZX turbo, but It turned out to be the EGR valve (Duh!) turns out the 300ZX I was looking at never came with a blow off valve, just a "pop-off" valve that ended up looking like a small tomato paste can coming out the side of the intake. The EGR looked closer as it looked like it vented to the exhaust like a traditional closed system blow off, but the vent is only .250-.375 max. I guess it could be made to work, but the blow off after closing the throttle would be too slow/drawn out, causing compressor stall?

What all are you trying to do? Let me first off say, any plastic bov will not work properly. Any eBay unit will out shine those ( I know, you are looking for size), also you need to tee into your vac. In the intake For a bov to work properly. The vacuum on the intake opens the bov. A bov that does not work properly will not let go of the charge air, throttle body closes, is a slam of air that has to go some where, which is right back into the turbo. bent fins, blown fins, blown seals bushings and compressor is just a start. I have even seen a turbo (eBay) break in half just because of bov. So, long story short, don't skimp here. Look on clist, there some good deals some times. And my bov is two inchs.

This is the one I and Another builder is using. Economical and the bench test was flawless. 2" in and 2" out!

http://cgi.ebay.com/ebaymotors/GODSPEED-...=item588f8e4253

I am using it with a B/W S480 80mm turbo.

Not that that is a bad bov, but just to point out, it is a knock off of a god speed knock off. I would love to see inside it. I just would hope that o ring is not the seal.

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Not that that is a bad bov, but just to point out, it is a knock off of a god speed knock off. I would love to see inside it. I just would hope that o ring is not the seal.

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I got it from God Speed! No it does not have an O-ring.. It has a reinforced diaphram that is a good piece. I did a bench test after I disassembled it and it held at 40 p.s.i... I also got the same wastegate and it had a torn o-ring in the adjustment on top. Polished the stem and added a new o-ring and bench tested to 40 p.s.i....
NO problems....