idle exhaust temps

Discussion in 'PSI Superchargers Tech Questions' started by Full Tilt, Jul 23, 2018.

  1. Full Tilt

    Full Tilt Member

    Joined:
    Jan 3, 2014
    Messages:
    70
    Likes Received:
    1
    what would a idle exhaust temp be approx
     
    #1
    Full Tilt, Jul 23, 2018
  2. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    Average of 450 but you will always have a couple that are hotter.
     
    #2
    Mike Canter, Jul 23, 2018
  3. Full Tilt

    Full Tilt Member

    Joined:
    Jan 3, 2014
    Messages:
    70
    Likes Received:
    1
    thanks mike , fired up new combo and have most at 399 to 450 number 7 at 295 , what would be the max on a run
     
    #3
    Full Tilt, Jul 24, 2018
  4. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    1050 is considered the max but have seen 1100 if running1/8 mile but that is risky
     
    #4
    Mike Canter, Jul 24, 2018
  5. rpt

    rpt New Member

    Joined:
    May 24, 2013
    Messages:
    20
    Likes Received:
    1
    Don't trust too much on the EGTs, put more care to the spark plugs.
    For example if youre too much retarded the EGTs will rise a lot because of the combustion continuing inside exhaust header.

    Mike can explain (and knows) this way better then me. Take a look at his guide on how to read plugs
    https://www.dragstuff.com/techarticles/reading-alcohol-spark-plugs.html
     
    #5
    Last edited: Jul 25, 2018
    rpt, Jul 25, 2018
    WIZBANG likes this.
  6. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
    Staff Member

    Joined:
    May 6, 2003
    Messages:
    6,706
    Likes Received:
    133
    there are a ton of variables that factor into the egt reading. Generally in the 1000-1050 is "safe" but I have burned stuff sub 1100 and I have seen mid 1100' readings leave cad on the plug.

    whether the probe is on the top or bottom of the tube can make a 80 degree swing on the same car.

    how far down the tube makes a difference. where the timing is. head flow, intake temp, etc., among a great many other things will all determine where the edge is for your particular combination.

    one of the reasons why I like checking bearings every run is they tell the tale!
     
    #6
    Will Hanna, Jul 30, 2018
  7. Mark Leigh

    Mark Leigh Member

    Joined:
    Mar 9, 2010
    Messages:
    446
    Likes Received:
    2
    When all you guys give recommendations on EGT's -- I have noticed that it depends on where the EGT is placed in the header on a set of FC headers for example --- the farther away from the port -- the higher the temp can be before trouble happens -- not sure if it's the same for zoomies ----
     
    #7
    Mark Leigh, Aug 2, 2018
  8. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    I believe there is a standard position for placement of the EGT sensors and that is 2.5” from the head flange area and the tips in the middle of the pipe. Most promods i have seen have always been on top of the pipe. But as already said there are many factors on the temps the biggest is timing. If you retard the ignition it moves the heat out into the pipe and EGTs increase Reading rod bearings will only tell you if you have gone too far. Reading the plug is the best source because it is right in the combustion chamber
     
    #8
    Mike Canter, Aug 2, 2018
  9. Ron C

    Ron C Jr. Dragster

    Joined:
    Mar 4, 2005
    Messages:
    519
    Likes Received:
    1
    Amen on reading the plugs,...it's a witness to the event.
     
    #9
    Ron C, Aug 2, 2018
  10. bill

    bill Member

    Joined:
    Dec 25, 2006
    Messages:
    103
    Likes Received:
    0
    does the egt probes ever go bad do they show a different reading or show blank on a race pak
     
    #10
    bill, Aug 18, 2018
  11. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    Yes th ey go bad all the time. Can either show a straight line at the bottom, random nose all over the screen or some low temp. Never seen one go bad and just be a hundred off.
     
    #11
    Mike Canter, Aug 18, 2018
  12. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
    Staff Member

    Joined:
    May 6, 2003
    Messages:
    6,706
    Likes Received:
    133
    Old trick learned from Gary Phillips - put your pyro's in boiling water, should read 212....
     
    #12
    Will Hanna, Aug 22, 2018
  13. Dave Koehler

    Dave Koehler Member

    Joined:
    Sep 10, 2004
    Messages:
    443
    Likes Received:
    14
    If your software allows it you can dial in each egt be changing the K factor or whatever it is called.
    The different lengths of wire will result in a different reading. At least that has been my experience.
     
    #13
    Dave Koehler, Aug 22, 2018
  14. vwsamba

    vwsamba Member

    Joined:
    Jun 3, 2006
    Messages:
    291
    Likes Received:
    3
    How do you help even then out at idle. Mine go from 350 on front cylinders to 750 on rear cylinders? 14/71 HHR littlefield blower with setback plate.
     
    #14
    vwsamba, May 28, 2021
  15. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    You can install a second nozzle system that drips fuel into the hot cylinders. You don’t make a run at idle so idle temps are not that important. More important is the temps during stage and during the run.
     
    #15
    Mike Canter, May 29, 2021

Share This Page





XenPorta 2 PRO © Jason Axelrod from 8WAYRUN.COM