Aftermarket boost guages
Boost-Happy Novice
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Aftermarket boost guages
Why is the 0psi in the middle of the guage. Who has boost taht runs at -12psi? Ya know I think it's a penis thing. I mean even though the boost only brings the needle up a quarter a way it loks like 3 quarters away so as to seem more badass. sorry if this makes no sense i'm buzzed and was just contemplating.
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vaccum is important in showing that your rings have sealed on a new motor, and that things are running fine on an already broken in motor.....
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Originally posted by Cronic
Indeed, it's not -12psi, It's 12 in of mercury (I think?) It's a measurement of vacuum...
Indeed, it's not -12psi, It's 12 in of mercury (I think?) It's a measurement of vacuum...
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Originally posted by Force Fed 23
Its inches of vacuum and very nice to know (although like a penis, if you have to ask what it is and what its used for, you probably don't need it).
Its inches of vacuum and very nice to know (although like a penis, if you have to ask what it is and what its used for, you probably don't need it).
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right, its important to have a Vaccum reading as well...
but a 12 in/hg vaccum reading means something is wrong.... really wrong. Normally on a good motor, youd want a reading of ~18in/Hg at idle, and about 20 in/hg of vaccum when coasting in gear or decelerating. Of course, a set of radical cams will change your valve timing events and alter your vaccum, and show LESS vaccum at idle. HKS 272's will drop your Vaccum ~ 2in/Hg overall and give you a lumpy idle.
THere are boost guages that are JUST boost gauges and go from 0psi-30psi or MORE and they start all the way on the Left side of the gauge... Autometer makes the and are designed for Roots-type blower equipped cars... ive seen plenty of "mullet-trons" and muscle cars w/ these guages and have no need for a vaccum reading since the Roots type is always pulling in air and compressing it so its always at positive manifold pressure.
My boost guage is Metric and reads boost in Kg/Cm2 and reads vaccumm in Kg/mm2 so i idle @ 550 kg/mm2, weird eh? oh, and im only running 0.5 Kg/Cm2... sounds pretty WEAK compared to "Dayum Y@, I be RuNin twenTy-Sizz1E... Nizz1e!!"
but a 12 in/hg vaccum reading means something is wrong.... really wrong. Normally on a good motor, youd want a reading of ~18in/Hg at idle, and about 20 in/hg of vaccum when coasting in gear or decelerating. Of course, a set of radical cams will change your valve timing events and alter your vaccum, and show LESS vaccum at idle. HKS 272's will drop your Vaccum ~ 2in/Hg overall and give you a lumpy idle.
THere are boost guages that are JUST boost gauges and go from 0psi-30psi or MORE and they start all the way on the Left side of the gauge... Autometer makes the and are designed for Roots-type blower equipped cars... ive seen plenty of "mullet-trons" and muscle cars w/ these guages and have no need for a vaccum reading since the Roots type is always pulling in air and compressing it so its always at positive manifold pressure.
My boost guage is Metric and reads boost in Kg/Cm2 and reads vaccumm in Kg/mm2 so i idle @ 550 kg/mm2, weird eh? oh, and im only running 0.5 Kg/Cm2... sounds pretty WEAK compared to "Dayum Y@, I be RuNin twenTy-Sizz1E... Nizz1e!!"
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Originally posted by flubyux2
right, its important to have a Vaccum reading as well...
but a 12 in/hg vaccum reading means something is wrong.... really wrong. Normally on a good motor, youd want a reading of ~18in/Hg at idle, and about 20 in/hg of vaccum when coasting in gear or decelerating. Of course, a set of radical cams will change your valve timing events and alter your vaccum, and show LESS vaccum at idle. HKS 272's will drop your Vaccum ~ 2in/Hg overall and give you a lumpy idle.
THere are boost guages that are JUST boost gauges and go from 0psi-30psi or MORE and they start all the way on the Left side of the gauge... Autometer makes the and are designed for Roots-type blower equipped cars... ive seen plenty of "mullet-trons" and muscle cars w/ these guages and have no need for a vaccum reading since the Roots type is always pulling in air and compressing it so its always at positive manifold pressure.
My boost guage is Metric and reads boost in Kg/Cm2 and reads vaccumm in Kg/mm2 so i idle @ 550 kg/mm2, weird eh? oh, and im only running 0.5 Kg/Cm2... sounds pretty WEAK compared to "Dayum Y@, I be RuNin twenTy-Sizz1E... Nizz1e!!"
right, its important to have a Vaccum reading as well...
but a 12 in/hg vaccum reading means something is wrong.... really wrong. Normally on a good motor, youd want a reading of ~18in/Hg at idle, and about 20 in/hg of vaccum when coasting in gear or decelerating. Of course, a set of radical cams will change your valve timing events and alter your vaccum, and show LESS vaccum at idle. HKS 272's will drop your Vaccum ~ 2in/Hg overall and give you a lumpy idle.
THere are boost guages that are JUST boost gauges and go from 0psi-30psi or MORE and they start all the way on the Left side of the gauge... Autometer makes the and are designed for Roots-type blower equipped cars... ive seen plenty of "mullet-trons" and muscle cars w/ these guages and have no need for a vaccum reading since the Roots type is always pulling in air and compressing it so its always at positive manifold pressure.
My boost guage is Metric and reads boost in Kg/Cm2 and reads vaccumm in Kg/mm2 so i idle @ 550 kg/mm2, weird eh? oh, and im only running 0.5 Kg/Cm2... sounds pretty WEAK compared to "Dayum Y@, I be RuNin twenTy-Sizz1E... Nizz1e!!"
I do know that my car puts up some sort of vacuum, because I once disconnected the boost gauge and just drove around with the hose pressed against my finger. Get into boost and air pressure comes out, let off and it sticks to your finger. It enjoyed the whole thing entirely too much, and drove around boosting and then letting off the gas pointlessly just to get it to switch between blowing out air and sucking air in. 
