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Thread: New 4L80E Overheating Issue

  1. #1
    Potential Tuner
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    Feb 2020
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    New 4L80E Overheating Issue

    I finally finished swapping my Camaro from a 4L60E to a 4L80E and have been doing some short drives to shakedown the car. Thing shifts beautifully, WOT shifts with are insane, but I hit one snag so far. I have a 3 mile uphill climb back to my house. I started with about 15 min of city driving, 15 min of interstate cruising (with a few WOT pulls) and back to 25-35 mph low throttle climb back to the house. Temps were between 140-160F until the uphill climb. I have an autometer gauge installed in the trans pan (standard pan) to monitor trans fluid temps. On my drive back my temp shot up from about 160F to 230F. I noticed the car revs a bit higher than I'd expect gong uphill. I'm trying to determine if this issue is mechanical or software related. I'm leaning towards tuning.

    With the old 4l60e I'd live in the 140-160F range. If I was thrashing on it, and brake boosting, I might manage 180F. I had an 10"x 20" x .5" tube and fin trans cooler in front of the radiator. Never figured out who made it but similar coolers has a 21000GVR. It filled the void in front of the radiator so air had to pass through it.

    With the 4L80E I changed the cooler and replaced all the stock lines with -6AN lines. I went to a Derale 19 row stacked plate cooler (Part Number 13403). This is in the same location in front of the radiator. It is not rated in GVR, but is rated to remove 37,000 BTU's Per Hour. I spoke with Derale, and even though the ratings are not comparable (tech said GVR cant convert BTU/h) he said the cooler is far superior. I also brought up the fact that the cooler was physically smaller and thicker. Could the air pass around it vs. through it reducing cooling capacity (ie. heatsoaking)? He said no.

    Upon doing the swap I had kept the tune completely stock, apart from shift scheduling. I have a Jake's Stg 3 4L80e and one of his billet triple clutch converters. 3800 stall. I've since compared the original 4l60e tune I had vs the new 4l80e tune I have and found the following differences that may be contributing:

    1. Torque Converter -> General -> TCC Duty Cycle -> Minimum table has low values - I've read that this is not ideal for a high stall converter and can cause heat. Will slip too much.
    2. Shift Pressures -> General -> Steady State General is enabled on current tune. Not sure how this works and is causing havoc.

    Took some tips off this thread: https://forum.hptuners.com/showthrea...CC-TM-(w-Pics)

    I think setting the TCC duty cycle max and min tables to 100% will alleviate my problem. I want to ensure I won't do any more harm by continuing to test. Also wanted to ensure there is nothing else I'm missing. I'm also tuning with the intention of maximum life. Willing to sacrifice drivability. I'll do some logging and post it after the fact. I have been reading about comparing the ISS and OSS to verify if the converter is slipping. Thanks for any comments.

    FYI - Used Bluecat to tune shift points

    "2002 Camaro 2.16.20.hpt" is the 4L60e file
    "Stock OS (PD COPY) - Trans Trans Diag Fuel Sys System Speedo" is the 4L80e file before the TCC duty mods
    "Stock OS with TCC duty correction.hpt" is setting TCC duty to 100% all the time.

  2. #2
    Senior Tuner kingtal0n's Avatar
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    Feb 2017
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    miami
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    Its overheating while locked up converter clutch in overdrive while cruising with light throttle? What is the commanded Amperage going to the transmission during the cruise? It should be fairly high near 1amp, say 800mA or something