-10 to -15 on boost gauge at idle???

[TurboDreamzGST]

Hey when I'm idling, my boost gauge will only read about -10 to about -15 and many people have told me it should be much higher than that, like around -20. Can anyone help me out and let me know why I'm having this problem? I have no boost leak and all my vaccuum lines seem to be ok. Please help.

 

[95GST2841]

with the a/c off I'm a little bit past 15

 

[RedTurboEclipse]

You sure you have no boost leaks? Did you check? Check compression. I have heard about many of what is normal. But basically its 15-20 during idle. And while cruising a lil more. Do a search and you will see more specifics. I hear elevation effects your numbers as well.Same thign with cams.

 

[brute]

Mine's steady at about -13 at idle. Decelleration in gear makes it go to about -21

 

[TSIMonsteR]

Anything below 15 at idle normally means you have a Vac leak of some sort

 

[itsover]

My use to be 24, then after I fix my Idle, it idle 16, is that ok ?

 

[Defiant]

Where, exactly, did you source your vacuum?
What sort of tubing did you use to the gauge?

 

[kenamond]

Mine's steady at about -13 at idle. Decelleration in gear makes it go to about -21

Mine's -14 idle and -20 during decel. We're both at a much higher altitude than the other folks, and that affects these vaccuum numbers.

 

[kenamond]

You can test for vac leaks by spraying your vac lines with some starter fluid during idle. If your idle increases, it's sucking the starter fluid through a leaking vac line.

 

[PieEyedPiper]

Just for reference to Kenamond's numbers being at high altitude;

I live at Sea Level and I pull around 18-19inHg at idle and about 28inHg when I decel.

 

[dsmgrimreaper]

hey if you have no boost leaks and the gauge is hooked up correct the dont worry about it,
if something isnt working right you'll know

 

[twack]

where would i check for vacum leaks

 

[GreyturboKJR]

my guage reads about -18 to -20 durring idle and depending on what is on ## car can have more or less vacum durring idle. as long as it runs good and shounds liker theres nothing wrong i would not be concernd.

 

[eclipseism]

Mine read anywhare from 19-20

 

[DodgeAvenger96]

Just for reference to Kenamond's numbers being at high altitude;

I live at Sea Level and I pull around 18-19inHg at idle and about 28inHg when I decel.

Yep the same here.

 

[donnyb1607]

Mine's steady at about -13 at idle. Deceleration in gear makes it go to about -21

my vac is the same,

id first check for vac and boost leaks. Also check your injector o-rings, they sometimes will cause a boost leak or vacuum leak.

 

[xrobbx03]

I live at sea level also and mine ready anywhere from -18 to -22 at idle

 

[RedTurboEclipse]

I believe timing also affects this. I was reading the writeup to install cams on RRE's site. They said if timing is off when the timing belt was installed improperly, it will show in the vac readings as well.

 

[Eclipse98_RS]

mine is about 17 when in decel, and 12-14 when at idle

 

[mitsu29]

Ok, i ve installed my boost gauge awhile back and never thought ive had a problem. I have the Blitz BLM series Boost/EGT Gauges, and frankly, im having a hard time with the psi/bar conversions, but not hard enough to change them. Now, i ve read on other threads that:
1 Bar = 14.5 Psi, and that should pretty much do the trick in terms of figuring out what my readings should be like. Now here is the part that im confused:

Most people say that the vac reading in park/neutral should read like what 16-20psi, but according to my gauge it maxes out at 14.5 psi? Is the vacuum side of the gauge a different metric than the psi side?

Heres a picture of my gauge:

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Now, when i m idling, im at the 0.5 mark exactly, is that where im supposed to be reading at? if so, what reading in metric-standard is the vacuum side? Please i really want to try and get all this down in my head, and the reason i ask is because im trying to figure out if i have a vacuum leak and is not causing me to 'blow-off' at idle like most of our cars. My assumption is that i am running fine with no leaks, but since i dont have the fuel upgrades neccessary, nor the boost controller, to set my boost, the reason im not 'blowing off' is simply because im set like at a low psi setting?

Anywhoo thats my assumption, but i want to be sure everything is running as it should be

 

[kenamond]

The problem is that we're all talking about vaccuum numbers in units of inches of mercury (in Hg), not bar. Most boost gauges have positive pressure (boost) in psi and vaccuum in in-Hg.

15 in-Hg is about 0.5 bar. If you want an exact conversion, Google a conversion tool; that's what I did.

 

[Defiant]

Or, maybe try the search on this site.

 

[Loewen21]

Sure those help defiant, but the conversion for Bar to in-Hg is different than the one from Bar to Psi. so thats only half the problem, when dealing with idle we want in-Hg

 

[Defiant]

.....

 

[kenamond]

Actually, I find it as fast as anything to type "convert bar to in Hg" into the Google search field. It responds with: "1 bar = 29.5333727 inches of mercury" along with some other useful links. And that gives you the exact conversion factor in case you need an accurate number.

Similarly, if you type in, "convert 15 in Hg to bar", it responds with, "15 inches of mercury = 0.5079 bar". I've found it quite handy.