ok i installed my boost gauge a week ago and i made sure that the boost line that plugs into the gauge would not leak "put like 8 zip ties on"!! so my problem is the gauge always red about "20- vacuum" at idle now i was messing around with this kid that has a 30R turbo sti "440whp" and i was running the car hard for a little while so i check my gauge at idle and now its reading "15- vacuum" as if i have a vacuum leak but i know its not from the line to the gauge though and it has not went back to normal for a day now so where could it be from and how do i check cause i know 15- vacuum is not rite can someone please help me out here.....thanks

 

you have to get/make/ or have some one do a boost leak test for you and you will find if you have any leaks. -20 for idol is a lil low i think. i only see that when im engine breaking as i wanna say stock cams -15 is about right for idol. do a leak test and you will find the culprit

 

15- is rite??? anyways very weird it went back to normal 19- why did this happen???

 

when i first put the gauge on before i put the 8 zip ties on the hose to the gauge was leaking a very little bit "it was about 14-/15-" so when i put the zip ties on it stoped the leak and stayed at 19- untill the problem i had? i just want to know what my vacuum at idle should be on my aftermarket gauge for someone who know about this please help thanks!

 

bump......what does evryone's aftermarket gauge read at idle???

 

900 to 1000rpm

 

My bad, I didn't see the "aftermarket" part that is my stock tach reads.

 

Mine, at 4000ft, read anywhere from 18-15, but now with cams it reads about -14 at idle. Not sure where in NY your at, but do you think altitude could come into play? I moved from GA (sea level) to Reno, NV and when I 1st moved here my boost gauge would read -20, but after a while it eventually settled to 18-15 like I mentioned. It would sometimes go to -20 as well. Sorry if that seems confusing sounding.

 

Usually -15 in hg. Sometimes it'll read 17-18 at idle, but not often. Engine braking is like -21-22 in hg.

 

highest Vac I have ever seen is -21, at idle im at 16/17, AEM Truboost

 

when you get a vacuum leak you get less vacuum right?

 

Use copper plumbing (fittings, ferrules, etc). Zip ties just can't provide enough tension for a reliable seal.

 

What about T-bolts for vacuum lines? I might try hose clamps or something. I'm paranoid about leaks.

[Not to clutter the thread, but are you on the EvoATL forums? You should definitely join. evoatlanta.com]

 

this is what i've had in my car

stock - 16 to 18

hks 272's - 14 to 16

comp 280+ - 10 to 12

 

mine is 18 or 19 at idle and 14 or 15 with AC on at idle