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Thread: Hellcat , ZF8, How to get Target shift points

  1. #1
    Tuner
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    Oct 2013
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    Hellcat , ZF8, How to get Target shift points

    Coming from GM, I've done a fair share of mopar stuff.. But the new ZF8's i haven't had alot of time to play with until lately.

    Bought my wife a 16' Hellcat, got some goodies to go on it, but i wanna just tune it first. I understand all the tuning side, but I'm having a hard time figuring out how to raise or lower shift point / shift rpm. Does anyone have a link or care to explain this?

  2. #2
    Advanced Tuner
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    May 2016
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    Did you figure it out? Just have a lot if tables go change really. They over complicate it

  3. #3
    Tuner in Training
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    Oct 2018
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    The tables are based on output shaft speed so you need to multiple by the gear ratio.

  4. #4
    Advanced Tuner
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    Sep 2008
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    Portersville, Pa
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    Quote Originally Posted by ddtech View Post
    Coming from GM, I've done a fair share of mopar stuff.. But the new ZF8's i haven't had alot of time to play with until lately.

    Bought my wife a 16' Hellcat, got some goodies to go on it, but i wanna just tune it first. I understand all the tuning side, but I'm having a hard time figuring out how to raise or lower shift point / shift rpm. Does anyone have a link or care to explain this?
    Derek, shoot me an email. I would be glad to assist you with this.
    Specializing in building and tuning 1000hp, daily driven, 9 second cars!

    www.ostdyno.com Shop Phone: 724-368-9000

  5. #5
    Tuner in Training
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    Feb 2019
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    I also sent you a email mike

  6. #6
    Potential Tuner
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    Aug 2019
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    Quote Originally Posted by Flipfloptrader View Post
    The tables are based on output shaft speed so you need to multiple by the gear ratio.
    what were looking to do is add 5% ( x 1.05 ) to an entire output shaft speed table for a given aggression number and trans setting, that will raise ALL the shifts 5%, or make changes to individual cells using the math ( OSS x GR ) Am I on the right track here?

  7. #7
    Tuner in Training
    Join Date
    Mar 2018
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    19
    Yes. You can make an easy Excel sheet to make a copy and paste table. Multiply OSS value by gear ratio to find commanded shift point. If you have a desired shift point in mind, simply divide by gear ratio to find OSS value to input.

    Note that trans will always shift past commanded shift value. Important to log trans to see how far your trans overshoots given gear on average, that way you know what to command.

  8. #8
    hi friends does any one have the stock 2015 zf8 hellcat file ? i have some issues at ver low throttle first to second shift , is slip a lot and need to compere with stock file that dont have it