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?