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Thread: Torque Based Shift Schedule safe to disable?

  1. #1
    Advanced Tuner
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    Torque Based Shift Schedule safe to disable?

    During severe wheelspin: I'm having an issue where the trans starts the shift from 1st into 2nd and due to torque reduction the tires sometimes catch traction and the car tries to go back to 1st then 2nd again! This causes me to hit my fuel cut limiter. Looking at the shift schedule it should never try to downshift to 1st until 30mph or lower yet it was much higher mph.

    I'm thinking this is the result of torque based shift scheduling overriding my normal schedule. Is it safe to disable?

    EDIT: I was thinking about when I had disabled torque based shift schedule in the past. It would run on it's own -hidden- schedule in which my changes to shift points were ignored so this probably isn't the solution. I lowered downshift prevention from 5500 back to stock 4500 to see if that helps.
    Last edited by blackbolt22; 07-14-2019 at 08:15 AM.
    Knock Retard is the reduction or prevention of knock by lowering ignition timing:

    (+) Adding Knock Retard = Reducing Timing. PCM is seeing knock.
    (--) Lowering Knock Retard = Increasing Timing. PCM isn't seeing knock.
    __________________________________________________ ________

    2014 Mustang GT Premium. VMP Gen2R Supercharged with an FTI 3000rpm Converter. JLT, BMR, Steeda, Viking, etc.
    Don't fix it if it ain't broken | Maximum effort gets maximum results

  2. #2
    Senior Tuner veeefour's Avatar
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    You need to fix your shift schedule and few other things - this could be dangerous on the road and you can actually end crashing your car.
    We had a car acting like that that was previously tuned by someone else - super sketchy tune and even more sketchy to drive.

    Do not disable your torque interventions - you will only make it worse.

  3. #3
    Advanced Tuner
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    Quote Originally Posted by veeefour View Post
    You need to fix your shift schedule and few other things - this could be dangerous on the road and you can actually end crashing your car.
    We had a car acting like that that was previously tuned by someone else - super sketchy tune and even more sketchy to drive.

    Do not disable your torque interventions - you will only make it worse.
    Found issue I think. I adjusted downshift prevention from 5500 to 4500 and this stopped a lot of issue. That said, after many tests it occurred once and I have reviewed the log:

    The rear wheels are spinning 40mph and car is going 20mph. When shift occurs (correctly) during wheel-spin, traction is regained putting rear wheel mph back to cars slow speed (now 28-30mph) in range for a 2>1 downshift. This was intentional as I like to be able to kickdown to 1st @ 5500rpm. I believe this is the problem.

    EDIT: Seems to be fixed only I can't downshift like I used to and it sucks lol. I will have to nudge it back up a little
    Last edited by blackbolt22; 07-16-2019 at 09:23 PM.
    Knock Retard is the reduction or prevention of knock by lowering ignition timing:

    (+) Adding Knock Retard = Reducing Timing. PCM is seeing knock.
    (--) Lowering Knock Retard = Increasing Timing. PCM isn't seeing knock.
    __________________________________________________ ________

    2014 Mustang GT Premium. VMP Gen2R Supercharged with an FTI 3000rpm Converter. JLT, BMR, Steeda, Viking, etc.
    Don't fix it if it ain't broken | Maximum effort gets maximum results