How to wire up an EGT and AFR gauge

Discussion in 'Modifications & DIY how-to' started by baddriver, May 6, 2006.

  1. baddriver

    baddriver Active Member

    What's the proper way wo wire in an EGT gauge on a WRX or sti?

    Where should the probe go or is it allready there and is there a bung for it?

    I'm guessing the closer to the exhaust port on the head the better. Is this correct.

    I've also heard things about the #3 cylender tending to run hot and lean due to it's proximity to the uppipe. Should things like egt and afr probes go near there?
     
  2. suby113

    suby113 Member

    EGT probe should be put right behind the turbo at the top of the downpipe. If you have after mkt exhaust like a perrin or invidia down pipe including cobb someof those have the bung for it.. if not you have to weld a bung in and screw the probe in. the AFR gets connected to your #2 O2 sensor in your mid pipe.
     
  3. moose

    moose Infina Mooooooose!

    I would recommend tapping the exhaust manifold for an EGT probe.

    Also, an AFR gauge serves little more purpose than giving you a nice lightshow unless you also install a wideband sensor. :)
     
  4. goixiz

    goixiz Active Member

    NOOOOOOOOOOOOO

    EGT has to be at the outlet of cylinder on manifold
    AF ratio is after Turbo.

    Stock does not have either of them available
    Aftermarket DP some does, your exhaust manifold in fact have a thick location for drill and tap.

    Scoobymods have an excellent write up
    http://www.scoobymods.com/forums/showthread.php?t=3367&highlight=EGT+probe
     
    Last edited: May 6, 2006
  5. baddriver

    baddriver Active Member

    Excellent with those EGT install docs from scoobymods. Very detailed. thanks!

    Thanks, I'm going to look for a downpipe with the extra bung for a wideband sensor. On my old car MY04 wrx I had a bosal catless divorced dp but wasn't to happy with the fit.

    I need to get a better undrestanding of what DP's I should mate to the VF39 turbo. I'd like to go catless, but I may have to have to port the turbo to avoid boost creep issues. I'm still tring to figure this one out.

    Anyone have a good procedure for porting a wastegate on a VF39, or know someone that can do this inexpensively?
     
    Last edited: May 6, 2006
  6. suby113

    suby113 Member

    I was just telling him the applications that I have noticed personally. Look at the cobb tunning down pipe! It has a bung for the EGT right behind the turbo on the down pipe. Although putting it right behind the outlet of the manifold is better it will work after the turbo as we'll. The stock EGT sensor is in the upipe, this I know for a fact because once I changed the upipe in my 04 wrx I was throwing an EGT code. The stock EGT looks like a needle at the top of the upipe. By the way does everyone try and make it a point to prove people wrong on here especially when someone is letting someone know how to do things from experience! I did all work on my 04 and on my stsi and someof my friends wrx's and this is where we had positioned these sensors nad have had no issues. Baddriver, my advise to you is depending on the downpipe you use look at that companies application for the EGT. Here is what the COBB one looks like.
     

    Attached Files:

  7. baddriver

    baddriver Active Member

    Thanks again.

    There wouldnt be anything stoping me from using the bung in that downpipe for a wideband afr probe would there?
     
  8. suby113

    suby113 Member

    I don't believe so, but having that to close to the Turbo may give you inaccurate readings and it may heat it up to much. usually it goes down stream towards the mid pipe where your stock cat used to be a little further from the heat of the turbo, by your, o2 sensor. You may want to ask Scott seigel or Top Speed about that, I have not used a wide band before, I normally used an AFR and connected it in line with the o2.
     
  9. moose

    moose Infina Mooooooose!

    And here's how Cobb describe it on their web site:

    Look, nobody's sitting around waiting to prove people wrong just out of spite, but we all want the information shared on the site to be as useful and accurate as possible; it helps people make better decisions that way. If people see somebody else post something they disagree with, they'll pipe up and say so. Nothing wrong with that.

    The stock EGT sensor is in that position because it's sitting right at the uppipe cat. It's not there to provide accurate EGT data for tuning purposes; it's there to make sure that the cat doesn't get too hot. In other words, it's more of a cat temp sensor than an EGT one. :) I'm with Ming on posititioning an aftermarket probe at the manifold.
     
  10. suby113

    suby113 Member

    True! and I agree with you totally! No harm done, just had a bad morning! just felt like I was obligated to tell what I knew.:bigthumb:
     
  11. miloman

    miloman Retired Admin

    this is not and WILL NEVER be the case
     
  12. suby113

    suby113 Member

    Ok Thats good to know ,I suppose I haven't been talking with you guys long enough to make assumptions, sorry if I had said that! just other forums like Nasioc just beet up on people that way, kinda used to it I guess. You guys are great here and this is truly the best Suby forum that I have been on. :bowdown: :p
     
  13. moose

    moose Infina Mooooooose!

    I think that mostly due to so many of us meeting in person now and then, things are friendlier and more civil here. It's easy to be an Internet tough guy and a big dick if you're safe behind a keyboard and likely will never meet any of the people you argue with in person.

    Really, we're all car enthusiasts and try to share as much information and help as we can. Sometimes we get proven wrong on things, but we all learn from it. It's all good. :)
     
  14. suby113

    suby113 Member

    Thanks! Hopefully one day soon I can take a trip to the ATl and meet you guys!:)
     
  15. Alex

    Alex Community Founder Staff Member

    We're a community built on helping others, and sometimes that help includes trying to put the most accurate information out there for everyone to use.
     
  16. goixiz

    goixiz Active Member

    yikes i didnt mean no harm
    hence the Nooooooooooooooooooo in a freindly manner
    ok next time ill include a smily :)

    I too learn from peoples postings and then my own errors
    but normally when i work on something ive never done before i spend 10 times more time searching and researching before i even tuirn the wrench

    hoping the wrench ferry will come and do that for me
     
  17. suby113

    suby113 Member

    Don't worry bro your cool!
     
  18. baddriver

    baddriver Active Member

    In addition to the members actively getting together for meets, drives and whatnot, I think the posts are better. Especially posts regarding sightings, mountain runs, tuners/mechanics, speed traps, things to do, or anything else area specific.

    There is more technical info on nasioc or the other boards, but it's nice to see so many subie enthusiasts who actually know each other posting here.
     
  19. moose

    moose Infina Mooooooose!

    You guys...

    :hug:
     
  20. GTscoob

    GTscoob Black is Beautiful

    I've got one in my Up-pipe that is very accurate. If you're UP has a bung just put it there, otherwise you'll have to take off the manifold and go get it tapped at a machine shop.

    I think the EGT after the turbo is a big myth, a lot of people talk of the temp sensors breaking off and destroying turbines. When I installed my EGT gauge, my stock EGT probe was just incinerated, there's no way it broke off, it just burnt up.
     

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