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hmmmmm.. does anyone know:
1. if there is a model of the F2 ProCharger with helical cut gears?
2. with a ProCharger engine (let's say it's setup for max boost 19-20psi @7000rpm) -when operating at low crankshaft speeds, say <2,500 rpm, would the intake manifold be in boost/vacuum sort of pressure zone or do they always be in boost ?



The "blow off valve" if you will, bleeds off boost. It works in conjunction with throttle blade position so i would think at that low of rpm you would be in vacuum but you may also have 1-5 psi by that time. fyi, ive seen upwards of 40 psi with an f-2 on a sbf overspinning the blower by about 10k