NAPARM

If a car (supercharged) makes 9 psi in 4th gear, does that mean it should also make 9 psi in 1st gear???
Reason i ask is because on the dyno my car was making just under 9psi but the max boost it makes in 1st gear (according to my boost gauge) is about 6 psi. Or are boost gauges not that accurate?

Cheers, Dave.

ebxr8240

If it was turocharged I'd say yes.But I guess load plays into it as well although with S/C boost is more linial to revs compared to turbo...Not that we are comparing...Also revs and load may not be taken as high in first gear...

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Xeron

Boost guages are accurate enough. ebxr8240 is on the right track with load to an extent. It's more to do with flow rates, in that at high revs you'll have more flow through the engine and in different gears you'll have different flow as well due to torque etc etc.

At least that's my theory, I'm no physicist. You can creep up the revs and not make any boost at all at times so that's my evidence. Hehe.

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Walkinshaw

what sort of supercharger? If its positive displacement then it should have the same boost regardless of gear. Technicaly same should be true of centrafugal.

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Ill take it as a complement i think.............

NAPARM

It's a centrifugal blower - 9psi Powerdyne.