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Thread: Calculated engine load vs absolute load

  1. #1
    Potential Tuner
    Join Date
    Jun 2019
    Posts
    4

    Calculated engine load vs absolute load

    Hey guys,

    So datalogging my M157,

    I wanted to see what the ecu engine load or engine tq was being measured at. is it accurate in HP tuners or we still waiting for updates.
    Last edited by 5soko; 11-02-2023 at 09:37 AM.

  2. #2
    it'll be referring to load. engine torque output means nothing and is solely for us. if your load tables are out of whack your transmission will do funky things.

  3. #3
    my best guess...but haven't spent to much time trying to figure this out

    maybe calculated engine load? When I alter the mapping enough to effect load values, my factory TCU begins to shift oddly. For example, shifting early in high gear, but not locking the convertor which wastes power and doesn't utilize the power being produced by the engine. amazing for drivability, but horrible for full throttle bursts. because of this, i do not alter my torque model maps any longer.
    Last edited by hachiroku; 01-31-2020 at 02:04 PM.

  4. #4
    Tuner in Training
    Join Date
    Jul 2018
    Posts
    22
    By "transmission doing funky things" Does any of this look like a wet clutch slip/flair under load?

  5. #5
    what will occur is... you'll have hard shifts at low throttle low RPM points or you'll have the transmission shift but not lock out in high throttle high RPM's. it'll have a split second of free rev before the transmission locks. not sure if this is the same for an MCT 722.9 transmission as those transmissions do not contain torque converters.

    essentially when the transmission is in auto shift mode if things are not in agreement you'll not have "positive shifting". a perfect engine tune will directly relate to perfect shifts by the TCU that are very smooth, fast, and direct. while not jarring or abrupt. this in turn would relate to "positive shift engagement". over the past week i have perfected my tune which has resulted in shifts better than factory new. the transmission is never doing something that i felt was odd. shifts are fast, direct, and seamless which results in quicker acceleration.
    Last edited by hachiroku; 02-17-2020 at 12:27 PM.