I'm trying to see if my boost guage (just installed) is reading accurately. At idle I'm sitting right around -15 to -16 psi. Does that sound right? Also, when things are quiet I can hear a very faint hissing noise from the guage (obviously there's a vacuum line...). Is that typical? Does the guage itself bleed off a tiny amount of vacuum (or boost) all the time? Thanks.

 

I think the average is about 18-20inHG. The gauge does not leak at all. One hose from the IM to the guage.
I run about 25inHG on a good day.

 

what have you doen to your car? if you have wild cams it could cause this or bad blow by. or you could just have a hole in the line

 

18hg/in

 

19-23 hg/in

 

18 - 20 in/hg

 

vaccum is @ 20....

 

Sounds like I have a leak in the line running to the guage. Internals on the motor are stock. (sigh) Guess that's the price I pay for having a "heavy handed" friend help me out. Hopefully it's just leaking right at the back of the guage. Thanks for the replies!!!

 

The harder I run my car, the stronger the vaccuum is. At cold start-up, it idles at 18, but warmed up it's around 20. After running the car hard, the vaccuum goes as high as 23 at idle. Anyone else find the same thing?

 

19-20 even with 1 cylinder leaking 70%

 

the warmer your car is the better they seal. also when you run your car hard you are most likely not running the ac so your vacuume will be higher.

 

Just because I know everyone has been worrying about this...

I found the leak at the back of my guage and fixed it with some tephlon tape (shoulda been on there to begin with). Now my idle sits right at -20 and off-throttle takes it to about -23. Thanks for the help y'all!!!