Mystickal

Vacuum is measured in " Hg which is inches of mercury. Vacuum gauges go from 0" to 30", with a measurement of 29.92" of mercury being a perfect vacuum. This stems from the use of mercury to measure barometric pressure.

~Bill

jimbo74

you should supercharge and turbocharge

YotaTruck1986

Thanks. How much vacuum would there be in a stock intake?

Well, I'd only do one. I probably goning scout the local junkyards for a 22RET.

Mystickal

It would vary. Bernoulli's principle tells us that as the velocity of air increases, the pressure decreases. So the amount of vacuum is going to depend on how fast the air is travelling through your intake, which will be a function of your RPMs, cylinder size, etc. etc.

A vacuum gauge is a useful diagnostic tool, especially on older vehicles that aren't fuel injected. They can tell you lots of things, if you know how to read them and what to look for.

Good idea. I'm sure he was only joking, doing both is a sure way to destroy your engine.

~Bill

YotaTruck1986

Thanks. Does anyone know what the bluebook value of a 1986 pickup with a 22RET is? Thanks.