idle vacuum psi

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turbo970
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idle vacuum psi

Post by turbo970 »

i been reading some threads and was wondering if -12 psi was a normal idle reading on a boost gauge. i read a few threads where others were having -18 psi at idle
alexandermf
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Re: idle vacuum psi

Post by alexandermf »

Me and Chris both run around 16-19 mine usually hovers over 18 with a warmed up idle. But i think our altitude has something to do with it vs vac readings at sea level


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turbo970
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Re: idle vacuum psi

Post by turbo970 »

i'm at 7000 ft above sea level but running a stock turbo
James614
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Re: idle vacuum psi

Post by James614 »

I pull 17-18 near idle. Id guess you have a vacuum leak.
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matt00rs25
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Re: idle vacuum psi

Post by matt00rs25 »

19-20 and I'm right at sea level
Legacy777
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Re: idle vacuum psi

Post by Legacy777 »

Idle vacuum is going to vary on elevation. Check out this post for the ambient pressure at different altitudes.

http://bbs.legacycentral.org/viewtopic. ... on#p381936

I think 12 in-hg is probably a little lower than it should be.
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turbo970
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Re: idle vacuum psi

Post by turbo970 »

i went threw all the vacuum lines today replaced 2 and zip tied them all. now at idle it reads -14 i cant figure out why it wont hit -18.
lucas
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Re: idle vacuum psi

Post by lucas »

because pressure altitude lowers it.
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Legacy777
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Re: idle vacuum psi

Post by Legacy777 »

Your vacuum reading of around 14 in-hg is about where it should be for 7,000 ft.
Josh

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turbo970
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Re: idle vacuum psi

Post by turbo970 »

it kind of bounces but it runs fine. i did notice my brake pedal got firmer after replacing the 2 vacuum lines. and the boost comes in a lil sooner. just wish i had the funds to do the td04 up grade
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