Boost Gauge Reading Vacuum..
Results 1 to 14 of 14

This is a discussion on Boost Gauge Reading Vacuum.. within the STi Technical Forum forums, part of the Tech & Modifying & General Repairs category; Hey guys I'm new here, and I'm sure this has been covered multiple times, but I can't seem to find ...

  1. #1
    Registered User
    Join Date
    Jan 2014
    Posts
    16

    Boost Gauge Reading Vacuum..

    Hey guys I'm new here, and I'm sure this has been covered multiple times, but I can't seem to find any info on why. I've connected the boost guage Tee just like I've seen on other forums, to the hose coming off of the OEM BOV, and ran my tubing back to the guage, I do hear a little bit of a leak around the gauge, is this normal? And why is it reading vacuum pressure and not boost pressure where I've connected it? Thanks guys

  2. Remove Advertisements
    ClubWRX.net
    Advertisements
     

  3. #2
    Registered User wreckingball man's Avatar
    Join Date
    Jul 2012
    Location
    Rocky Top
    Posts
    2,276
    At idle and during most driving the system is in vacuum. You will only read positive atmosphere when you're turbo is spooled and compressing the air.

  4. #3
    He simply abides. SD_GR's Avatar
    Join Date
    Jul 2002
    Location
    CA, US
    Posts
    22,600
    I Support ClubWRX
    Quote Originally Posted by GODSTILLA View Post
    Hey guys I'm new here, and I'm sure this has been covered multiple times, but I can't seem to find any info on why. I've connected the boost guage Tee just like I've seen on other forums, to the hose coming off of the OEM BOV, and ran my tubing back to the guage, I do hear a little bit of a leak around the gauge, is this normal?
    No. Fix the leak.

    And why is it reading vacuum pressure and not boost pressure where I've connected it? Thanks guys
    Because the manifold is under vacuum, not boost, at those times. You should see it go past atmospheric pressure (or "zero") and into boost though if you have enough spool.
    WRX Info Links, Courtesy TheJ
    The world breaks everyone and afterward many are strong in the broken places. Ernest Hemingway
    I lied. I cheated. I bribed men to cover the crimes of other men. I am an accessory to murder. But the most damning thing of all... I think I can live with it. And if I had to do it all over again - I would. Benjamin Sisko
    DISCLAIMER: Opinions expressed are the author's alone and are inherently worthless.

  5. #4
    Registered User preston_nfs's Avatar
    Join Date
    Sep 2012
    Location
    Toronto, Ontario
    Posts
    29
    You also shouldn't hear anything around the gauge, sounds like there could be a leak.

    *edit*

    SD_GR beat me to it.
    2011 Subaru Impreza WRX (Plasma Blue Pearl)

  6. #5
    Registered User
    Join Date
    Jul 2011
    Location
    Hunterdon County
    Posts
    117
    You shouldn't be getting any sort of leak around the gauge. You are going to want to find the source/patch that baby up. You're readings are going to be of with a leak in the system.

    You should be reading vacuum at idle/deceleration/some cruise situations. Pretty much anytime there isn't a load on the engine you are going to read vacuum.

    When you put a load on the engine such as accelerating or driving up a hill you will start reading boost in the positive numbers.

  7. #6
    Registered User
    Join Date
    Jan 2014
    Posts
    16
    Ok. I'll go Ahead and put a clamp on the guage, now what's happening is that It'll read 10 Vacuum and then when I give it gas it'll just go to 0, It wont go any higher even at WOT. I just want to make sure that the place on the BOV the small hose, is the correct place to Tee it off at? Hopefully when I clamp down that hose it should fix it but I'm starting to have my doubts given that It wont go above 0. lol

  8. #7
    Registered User Ingo's Avatar
    Join Date
    Mar 2012
    Location
    Colorado Springs, CO
    Posts
    1,110
    What year car are we talking? With that someone will be able to give you the right info as to where to t-in.
    You can't have everything - where would you put it?

  9. #8
    Registered User
    Join Date
    Jan 2014
    Posts
    16
    haha Sorry I guess that would be some important info, it's an 06 STI, I attached it right at the BOV, where there was the small guage vacuum line

  10. #9
    Registered User
    Join Date
    Jan 2014
    Posts
    16
    OK, I think I figured out the problem, As I was making a video to show all of you I saw that my T had broken in half, so Immediately went to the auto parts stor got a new T and a new Vacuum line. I have it installed now and the guage reads 20 Vacuum and then when I go WOT it shows 10 pounds, just wanted to make sure this all sounds correct? I was under the impression I should be running about 13-14 lbs?

  11. #10
    He simply abides. SD_GR's Avatar
    Join Date
    Jul 2002
    Location
    CA, US
    Posts
    22,600
    I Support ClubWRX
    Max boost will differ according to gear and load, but in general you aren't wrong; your max boost should be a bit higher, yes.
    WRX Info Links, Courtesy TheJ
    The world breaks everyone and afterward many are strong in the broken places. Ernest Hemingway
    I lied. I cheated. I bribed men to cover the crimes of other men. I am an accessory to murder. But the most damning thing of all... I think I can live with it. And if I had to do it all over again - I would. Benjamin Sisko
    DISCLAIMER: Opinions expressed are the author's alone and are inherently worthless.

  12. #11
    UnBanned Sinister's Avatar
    Join Date
    Nov 2006
    Location
    Denver Metro Area
    Posts
    17,628
    I Support ClubWRX
    Quote Originally Posted by GODSTILLA View Post
    OK, I think I figured out the problem, As I was making a video to show all of you I saw that my T had broken in half, so Immediately went to the auto parts stor got a new T and a new Vacuum line. I have it installed now and the guage reads 20 Vacuum and then when I go WOT it shows 10 pounds, just wanted to make sure this all sounds correct? I was under the impression I should be running about 13-14 lbs?
    What does the gauge read when the engine is off? What altitude are you at? Is it mechanical or electronic (the sensor, not the display). Does it have a calibrate option?
    Kevin
    Moderator
    Sinister's Blowoff Valve FAQ
    WRX Gas Mileage FAQ
    Sinister's Progress Thread - 430whp 429wtq - Sold
    Firearms Enthusiasts Thread

    The Sheriff's Star at the bottom left corner rates a user's reputation.
    If you found a user's post to be helpful or quite the opposite, please make it known to them by clicking the Star!

  13. #12
    Registered User wreckingball man's Avatar
    Join Date
    Jul 2012
    Location
    Rocky Top
    Posts
    2,276
    Side note, why do some boost gauges read slightly less than zero when the engine is shut off? build quality of the guage, Boyle's law phenomena..lol

  14. #13
    Registered User
    Join Date
    Jan 2014
    Posts
    16
    Guage reads 0, it's a little below the Middle of the "0 range" but it reads 0 when motors off. Im about 2000 above sea level, mechanical, it's kind of a cheapy one from oreilly's it was $30, No Calibration option. Now I guess it could be the guage being that it was only 30 bucks, now I'm planning on replacing it with one of the prosport Evo Gauges, have you guys had any luck or reviews on them? Here's a link to them
    Prosport Gauges Evo series gauges, EVO Red and Blue digital gauges

  15. #14
    Registered User wreckingball man's Avatar
    Join Date
    Jul 2012
    Location
    Rocky Top
    Posts
    2,276
    I don't like prosport and I've owned them, mechanical and electrical. The mechanical gauges are ok and they do the job, but neither type was very accurate. Due to the way they are wired I couldn't dim them and they were much too bright for me. They're just basic and about worth the price. Not garbage, but not great either. I would just hold on to the money and get something a little better.

    *Opinion, grain of salt.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •