MAP pressure question.
06-23-2007, 10:27 AM
#1
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Location: Kantuckee Yo'
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MAP pressure question.
My MAP on the scanmaster reads 17.5 "HG.
I hooked my mity-vac up to the intake fitting that goes to the brake booster, it read 12" HG.
Will this affect A/F or brakes?
Do I have a problem here?
Thanks
I hooked my mity-vac up to the intake fitting that goes to the brake booster, it read 12" HG.
Will this affect A/F or brakes?
Do I have a problem here?
Thanks
06-23-2007, 11:12 AM
#2
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Location: Melvindale, MI, US
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GMs are a little wierd here, that 17.5 gets subtracted from the BARO reading, usually 28-30, so, 29-17.5=11.5, so, you have low vacuum
you might have OK brakes
06-23-2007, 11:40 AM
#3
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Location: Hell was full so they sent me to NJ
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Nothing "wierd" about GM.... its basic physics. MAP is by definition the pressure in the intake manifold referenced to absolute pressure (0 psi/0 "Hg/0 kPa)). Vacuum is the pressure in the manifold referenced to atmospheric pressure (approx 14.7 psi/29.92 "Hg/101.5 kPa at sea level).
To understand the MAP reading on your ScanMaster and how to convert it to vacuum, read this:
http://members.aol.com/InjuneerZZ/ScanMast.htm
To understand the MAP reading on your ScanMaster and how to convert it to vacuum, read this:
http://members.aol.com/InjuneerZZ/ScanMast.htm
06-23-2007, 12:05 PM
#4
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Anybody have any solid facts that this 12" HG is inadequate for full LS1 brakes?
06-23-2007, 12:35 PM
#5
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Location: Ocala, Florida
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My cam's probably around the same size as yours and I'm running C5 brakes up front. The pedal is stiffer than cars with a stock cam, but they still work fine you just have to push a little harder. I actually like the stiffer pedal.
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