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Thread: 6R80 14 GT always shifts early

  1. #1
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    6R80 14 GT always shifts early

    Editing this top post to correspond with all of my testing:

    My 14GT from a dead stop WOT commands shift @ 31-32mph causing the actual shift to occur at 6200-6300rpm for 1st to 2nd no matter what I set on any schedule anywhere in the tune. I've tried 20mph to 47mph in the last 4 rows of every 1>2 including traction control schedule.. From a roll a downshift to 1st then upshift to 2nd, it WILL follow the normal schedule! It's only from a dead that it's on the ghost schedule.

    It will shift at the traction control schedule if I trigger traction control. I've tried disabling trac control too but no dice. Disabling torque based shift scheduling causes the above to occur 100% of the time. Enabling torque based shift scheduling causes it to shift 1>2 at 7k every single time again ignoring any schedule in the tune.

    2>3, and 3>4 shift follow exactly what I schedule and I've had great luck with tuning these points with antic shifts disabled or enabled... it's simple.. one is a begin shift and one is an end.. easy concept.

    MPH, RPM, etc. etc. doesn't matter.. I've done crazy tests like set all schedules to 20mph for 1>2 in every table and nearly every row.. it still commands at 31-32mph!

    I've seen other threads posting about this issue but never a resolution. My strategy does NOT contain WOT RPM shift points for any other schedule except Normal schedule and "Trans RPM for Normal Engine speed Limit" doesn't exist in my strat either.. I've seen the latter set to 5500 as a FIX to this issue.. not sure how or why though. I've sent the e-mail to support hoping they will add it to my strat.

    Here is an example in the same log, with torque based schedule on where it's commanded at 36mph, and then I stop and do it again and it's on the ghost schedule, commanded at 32mph.
    commandedat36mph.PNGcommandedat32mph.PNG
    Last edited by blackbolt22; 08-21-2018 at 07:17 AM.

  2. #2
    Advanced Tuner LastPlace's Avatar
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    You would have to command a much higher rpm then your targeted with antic shift on.

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    Quote Originally Posted by LastPlace View Post
    You would have to command a much higher rpm then your targeted with antic shift on.
    Shift RPM Normal - WOT was set at 6800 for 1>2, 2>3, 3>4. It's shifting at 6350 and 39mph. 2nd shifts at 71mph and 6500.

    So it's off by 450RPM, so make it (6800+450=) 7250 for First.. and so on? So make MPH and RPM both much higher?

  4. #4
    Advanced Tuner LastPlace's Avatar
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    Leave it turned off and roll with it like your original post stated.

  5. #5
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    I might but I feel like antic. shifts might be more adaptive and even accurate once dialed in... It certainly doesn't seem like it right now though lol

  6. #6
    Advanced Tuner LastPlace's Avatar
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    Turn anticipated shift off

  7. #7
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    I leave anticipated shifts on, once dialed in its easy as moving shift rpm where you want it. Get your shift pressures where you want them first. Max out max accel, make sure your wot shift mph is higher than your shift rpm, and get your clutch fill time correct. Doing this I can get 1000hp cars shifting where I want them to every time using just the RPM shift points. 1st gear in high hp cars is too quick for anticipated shift to work correctly so you just got to get a little creative in that situation, but it will work. 2nd-4th will shift within a few hundred RPM of where its commanded doing this.

    To dial in clutch fill time I look at the time when the shift is commanded and when the shift actually happens and subtract the two times. Use that time as a starting point which will be pretty close to getting the car to shift at your target RPM. Never seen anybody else do it this way, but it works for me. Hope this helps.

  8. #8
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    Quote Originally Posted by Stang910 View Post
    I leave anticipated shifts on, once dialed in its easy as moving shift rpm where you want it. Get your shift pressures where you want them first. Max out max accel, make sure your wot shift mph is higher than your shift rpm, and get your clutch fill time correct. Doing this I can get 1000hp cars shifting where I want them to every time using just the RPM shift points. 1st gear in high hp cars is too quick for anticipated shift to work correctly so you just got to get a little creative in that situation, but it will work. 2nd-4th will shift within a few hundred RPM of where its commanded doing this.

    To dial in clutch fill time I look at the time when the shift is commanded and when the shift actually happens and subtract the two times. Use that time as a starting point which will be pretty close to getting the car to shift at your target RPM. Never seen anybody else do it this way, but it works for me. Hope this helps.
    My car is bone stock except for GT500 mufflers and no resonator. Do I still have to adjust clutch fill time? Whether antic shifting is enabled or disabled.. from a roll downshift to 1st and then shift to 2nd it follows the schedule.. if I go from a dead stop it short shifts and I can set MPH and RPM super high and it makes no difference, it always commands at the early shift point. The commanded mph is not in any shift schedule table.. I can't understand why it would do that. I thought for a while it was traction control however I maxed every row mph and turned advance trac off.. still acts the same. Also tried the last 4 rows putting MPH high, no change. It's like from a dead something gets triggered that overrides the schedule.

    If I dial in clutch fill times with antic on.. this is the key to getting it timed out correctly?

    Thank you for the helpful reply! I'll look at the logs again tomorrow and check the times in my tune.
    Last edited by blackbolt22; 08-13-2018 at 11:36 PM.

  9. #9
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    It sounds like your spinning when it shifts early. What happens is your gaining mph and rpm at a faster rate so it commands the shift earlier than if not spinning. Your actual speed starts to match your spinning speed at higher rpm which brings your rpm back down. Since the shift was already commanded about .5 second earlier you get an early shift.

  10. #10
    If the car isnt spinning

    Whats the solution

  11. #11
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    Quote Originally Posted by elerico View Post
    If the car isnt spinning

    Whats the solution
    Spinning ultimately wasn't the issue for me and neither was N/V settings (they were already right but can definitely play a factor). After this post I turned antic shifting off and just raised MPH high enough but not too high. This seemed to be the magic fix.

    Now that I have a torque converter and supercharger, I'm trying my hand at antic shifting enabled and still using the strategy I mentioned about MPH. It's much trickier with a slippery converter to get shift points right but I got it!
    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.
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    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

  12. #12
    Hey Blackbolt any chance you could shoot me your file we have similar setups and I’m trying to get a grip on auto tuning with a loose converter and not smack my head against the wall lol. Much appreciated brother.