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vacuum gauge

DaGr81

By DaGr81,
in Engines & Forced Induction

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DaGr81 Mentor

DaGr81

Posted
Posted

can sum1 tell me wat a vacuum gauge does? i got a whole bunch of gauges off a mate derno wat this 1 does, ive used some of the gauges in my gtst but id like to have sum in my gts as well, wud it work in the gts?

any info wud be much appreciated

ta

:)

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Sneaker Enthusiast

Sneaker

Posted
Posted

It will work in the GTS but will only show you off boost properties. It was used in N/A cars for years as a sort of economy guage.

How does it work? The less you have your foot down the more your throttle is closed and therefore the more vacuum is created in the inlet plenum and hence the gauge reading. Wide open throttle results in little vacuum which reads as "Power" on the guage.

Even the some of the recent BMW's still used this but went as far as putting litres per hundred figures on there!

Yes it will fit but as soon as the turbo kick in it will be of no use, in fact the turbo will through the accuracy of the gauge out. If you really want one, get one that has both boost and vacuum in one. When the guage hits "0" then, it means the turbo is feeding the exact amount of air that the engine is sucking - relative boost is 0.

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Jordan Rising Star

Jordan

Posted
Posted
It will work in the GTS but will only show you off boost properties. It was used in N/A cars for years as a sort of economy guage.

How does it work? The less you have your foot down the more your throttle is closed and therefore the more vacuum is created in the inlet plenum and hence the gauge reading. Wide open throttle results in little vacuum which reads as "Power" on the guage.

.

You got the right idea, but your all backwards.

The engine is sucking on the intake plenum like a guy sucking up a thickshake with a straw. The harder the guy sucks, the more vacuum is created.

(The more resistance on the intake side of the engine, the more vacuum is made.)

When the throttlebody is only cracked open a little and the car is cruising along, its not sucking in that much air, hence less vacuume will show because the guage will be getting closer and closer to 1 bar(omatric) unit of pressure, which is 14.7psi, depending on your altitude of course.

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