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Thread: 68RFE Parameters

  1. #1

    68RFE Parameters

    Hello, who would I talk to about getting HPTuners to dive deeper into the trans parameters of the 68RFE transmissions. There's a handful of really valuable parameters that we are missing access to.
    Thanks for the help
    Best Regards,
    Dominic

  2. #2
    Must have already been in the works, looks like they just released the LR ON for the low sprag fix.
    Hopefully they will dig deaper into being able to keep the Converter locked during shifts.

  3. #3
    I am excited to try out the L/R Sprag option. Are you able to explain what the sprag is used for? I believe the sprag is bypassed when using the ERS function, so do we really need it? I also believe the ATS Co-Pilot bypasses the sprag.

  4. #4
    Yes the copilot does bypass it. It is needed for keeping the Low Sprag from flipping under high power in 1st gear. The Low Sprag in the 68rfe was a poor design, was not like the 48's that have a spring in them to keep tension in the direction of rotation. So when the clutch releases it shocks the sprag and if done enough times it will cause catastrophic damage to the sprag. Being able to bypass the LR Sprag allows you to be able to do boosted launches or full power 1st to 2nd shifts without worrying about braking the sprag.
    Last edited by Dom_c13b; 08-22-2017 at 09:41 PM.

  5. #5
    So to bypass the sprag, would I need to have the L/R clutches stay engaged past 150rpm? Pretty much keep them engaged until the 1-2 shift?

  6. #6
    Yes exactly. Keep it engaged til 900+ RPM

  7. #7
    Thanks! It does make me wonder for the stock transmission, why do the L/R clutches disengage after 150rpm when just drive is selected, yet they stay engaged when using the ERS function? Why have the sprag?

  8. #8
    Not sure, I admittedly don't know enough about the 68rfe yet. I build 48's often enoguh but have never had a 68 apart. I actually just bought the manual yesterday so that I can start looking into what makes them tick. I have tuned a lot of them but really should know more about them in order to get the best tuning possible.

  9. #9
    I would like to thank HP Tuners for continuing to develop functions for the RFE transmissions. One critical function that would be nice would be the ability to perform a quick learn to reestablish the CVI values after a transmission has been rebuilt or modified. Just throwing that out there for any developers.

  10. #10
    I agree, that along with the ability to keep the converter locked through all shifts would really help make this trans perform nicely.

  11. #11
    Potential Tuner
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    I know this is a extremely old forum but can i go in and tune a 68rfe that is a 3rd gen through the obd2 or no?

  12. #12
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