Normal Vacuum Reading
11-20-2007, 10:58 PM
#1
Member
Thread Starter
Normal Vacuum Reading
I have a 1988 l03.
it is plain old stock.
What should the vacuum be at idle?
According to the gauge in my gauge pod, I have about 5 0r 6.
This seems low. Is it low?
BTW What are the units for measuring vacuum, monkeys?
Just kidding, I am interested in the unit of measure for vacuum.
THANKS.
it is plain old stock.
What should the vacuum be at idle?
According to the gauge in my gauge pod, I have about 5 0r 6.
This seems low. Is it low?
BTW What are the units for measuring vacuum, monkeys?
Just kidding, I am interested in the unit of measure for vacuum.
THANKS.
Last edited by copperhead110; 10-25-2021 at 08:16 PM.
11-21-2007, 12:33 AM
#2
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
The typical units are "in-Hg" - or inches of mercury.
Imagine a glass tube stuck in a pool of mercury standing straight up. You attach the vacuum hose on the top end of the tube. Mercury is sucked up into the tube. The greater the vacuum, the higher the mercury is sucked up into the tube.
If your pod gage is calibrated in in-Hg, that means it thinks the mercury would rise up 5-6 inches in the tube above the top of the pool of mercury.
Normal for a stock LO3 is more like the 18-20 in-Hg range.
Imagine a glass tube stuck in a pool of mercury standing straight up. You attach the vacuum hose on the top end of the tube. Mercury is sucked up into the tube. The greater the vacuum, the higher the mercury is sucked up into the tube.
If your pod gage is calibrated in in-Hg, that means it thinks the mercury would rise up 5-6 inches in the tube above the top of the pool of mercury.
Normal for a stock LO3 is more like the 18-20 in-Hg range.
11-25-2007, 08:08 PM
#3
Member
Thread Starter
Re: Normal Vacuum Reading
Thanks for the info.
The vacuum hose from the front of the throttle body to the underside of the air cleaner was disconnected.
Now the gauge reads 19.
The vacuum hose from the front of the throttle body to the underside of the air cleaner was disconnected.
Now the gauge reads 19.
Last edited by copperhead110; 10-25-2021 at 08:15 PM.
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