1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

EGT and WT Gauge with a supercharger

Discussion in '80-Series Tech' started by LandCruiserPhil, Mar 23, 2004.

  1. LandCruiserPhil

    LandCruiserPhil Peter Pan Syndrome Supporting Vendor

    Messages:
    19,259
    Media:
    55
    Albums:
    3
    Likes Received:
    7,940
    Joined:
    Mar 10, 2004
    Location:
    Scottsdale Arizona
    For the guys that run a supercharger equipped with an EGT and WT gauge.

    Does water temp always go up when with exhaust temp rises?
    What is the relationship of the two under conditions?
    Is it possible to be running cool up the hill with EGT sky high?
    Is there a real need for both gauges?
    How important is where and how you pick up your EGT from or are you just looking for a base line?

    Sorry for all the question but until I purchase and install them I just itching to know what I’ll find. and if I need both gauges.

    Also I’m new to the supercharger and being from Arizona the heat issue has me concerned. So all feedback is appreciative.


    Phil
     
  2. ppc

    ppc M Go Blue

    Messages:
    1,694
    Likes Received:
    341
    Joined:
    Aug 18, 2003
    Location:
    Nashville, TN
    See my post tonight on this thread:

    https://forum.ih8mud.com/index.php?board=2;action=display;threadid=13504

    The only person that I know that has done anything by adding a WT gauge is Photoman and I think he still is in the process. We have concluded that the OEM gauge is not much better than an idiot light.

    In another thread someone has stated that a oil temp gauge would show a better picture. The cooling system if operating properly can dissipate a lot of heat but I would still think that when EGT rises the water temp will be impacted to a certain degree but not necessarily immediately.

    I have an EGT, A/F and boost currently. The boost gauge after the first week is more of a gimmick but if there were some type of problem has some minimal value. The same is true for the A/F under normal conditions. Just a bunch of bling bling that everyone that gets into my truck is impressed with. When the engine goes rich and lean, like when my fuel pump started to fail, it indicates the condition quickly but that could be done with a simple warning light as well taking less space. EGT is extremely important. I'm addressing the water temp first by improving the OEM gauge or go aftermarket and then follow with experiments with oil temp if nobody is willing to take the plunge first.
     
  3. Scamper

    Scamper

    Messages:
    1,460
    Likes Received:
    2
    Joined:
    Mar 28, 2003
    Location:
    Somewhere in NJ
    Phil's comments were dead on in this post and the earlier one (really nice writeup Phil!).

    I have a '97 and installed my probe about 6 inches below the exhaust pipe/manifold junction (see ttp://www.geocities.com/george_tlc/scharger.html for a good writeup by George S.). Placement does make a difference in the temps you'll see simply becuase the exhaust gas will cool down as it passes thru the system. The idea behind placing the probe close to the manifold is so that you will be monitoring temps that more closely reflect what your engine is seeing. But the key point as Phil mentions is the relative changes in EGTs while you're driving under different conditions. For example, if you were to place your probe far down the exhaust pipe (where you'd see lower temps), it would probably not be wise to run up to temps as high as 1500° since your engine would be much hotter in reality.

    Whether its because of a slight difference in probe placement, different engine type, probe variations, or whatever, I see slightly lower temps than Phil describes (about 50-75°F), but again, what's important is the relative changes and how brown-proof you trousers are.

    You asked about whether the WT and EGT rise together...the EGT is very responsive to input such that you see the needle move pretty quickly when conditions change even slightly. At idle, I run less than 1000°, but that moves up in mere seconds as soon as you press the accelerator. You probably won't see this reflected in the WT readings unless you're on a long stretch and you've exceeded the cooling capacity of your system (however this is probably dependent on where the WT probe is located, and if it were in the head, it might show a slow increase when under load even without maxing out the cooling capacity). I've never seen my OEM idiot gauge move at all.

    I've not added any additional gauges, but if I were to do so, it would be either the WT or A/T (or both?). I'm also thinking of just getting one of those Palm OBDII scanners so that I can monitor all sorts of things as I drive. Now that towing season is rapidly approaching, I'm more inclined to do so...
    Tom
     
  4. Photoman

    Photoman SILVER Star

    Messages:
    1,151
    Media:
    41
    Albums:
    3
    Likes Received:
    65
    Joined:
    Mar 28, 2003
    I ran with a WT, boost, and EGT gauge for a year or so before I parked it. As ppc said the boost gauge is sort of a gimmick. I do watch it some time if I'm driving into the wind or up a hill. It is surprising sometimes to see I'm into boost.
    I have found that basically the temps do rise with the EGT's, although as Tom said it is slightly behind the EGT curve. The stock gauge does not show this much, but with a good WT gauge it can be seen. My EGT is mounted in the collecter pipe as I'm running headers so it is downstream. The only other alternative was to pick a cylinder to monitor. FWIW, my temp gauge was mounted in the block drain, which worked fine, but probably showed different temps than the head. Since I use warning type gauges it was all relative.

    Bill