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Thread: 4L80 swap shift point help

  1. #1

    4L80 swap shift point help

    I have a 07 Silverado with a 4l80 swap. The stock harness was repinned for the swap. Built 6.0 with TTs and I want shifts at 6800rpm. Everything else is working great except the WOT shift points. Tranny Specs are as follows:

    Jake's stage 3 4l80 with trans brake valve body
    FTI 3500
    3.42 rear gear
    30" tire

    I've set the shift points to hit at 6800 but no matter how high I set the shift points it still hits at 6000 rpm. Anybody run into this issue? I've seen guys have issues with the trans not shifting and banging the rev limiter but not an issue where the trans shifts out too early.

    Last log and tune

    19-02-01 16-14-58.hpl
    6.0.hpt
    RAW Racing in Tampa, Fla.
    Providing custom LS tuning and performance upgrades.

  2. #2
    Tuner in Training
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    I'm still learning this but just looking at your log I'm seeing your tps beginning to drop @ 5750rpm shortly after you move out of the WOT shift tables into the performance table. By this log I can only assume your letting out of it. Can you post another log with max tps through the entire shift and beyond with current gear and any pertaining parameters logged as well.

  3. #3
    Senior Tuner Lakegoat's Avatar
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    Looks like you let off the gas at 5700 rpm in the chart. Lets see where it is shifting wot thru at least first and second. That's where you can set your shift tables. Your computer needs to see the mph made and then the rpm. If they match, it will shift where it is supposed to. Looks like at 6000 rpm, you are going about 93. Your shift chart says 115 mph shift speed 2--3. You might be a little high on the mph. It needs to be about 8mph lower than the actual speed at 6800 rpm. And make the last two cells (94 and 100)% the same number. If you settle on 115 then make both those blocks 115 to give the computer some time. Then interpolate backwards a few cells to smooth.
    2000 Camaro SS 2015 L83 port injected, Whipple 3.0, 4L80E, 8.8 Ford
    2013 Silverado 5.3, 6L80k 8.8

  4. #4
    Thanks for the replies. Guys I don?t let off. This is on my dyno and the truck up shifts. I?m gonna try setting everything from 80% TPS to 100 at the same speed and see what that does today. I?ll keep you updated.

  5. #5
    Senior Tuner Lakegoat's Avatar
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    If you look at the pedal position, it goes from 99% steady and then drops at 5700 rpm. If that's where it shifts, the pedal position should stay at 99%, only rpm should drop. Which computer is this? May be a torque function.
    2000 Camaro SS 2015 L83 port injected, Whipple 3.0, 4L80E, 8.8 Ford
    2013 Silverado 5.3, 6L80k 8.8

  6. #6
    I appreciate your help and I know what you?re talking about and that wasn?t the issue. I figured it out, it was a speed limiter that was still at 98mph. She?s spinning up to 7k rpm now.

  7. #7
    Tuner in Training
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    Speed limiter lol wow, I saw the ETC set to 256mph figured the other tables were maxed as well, that would explain the TPS reading dropping, thanks for the update!

  8. #8
    Tuning Addict 5FDP's Avatar
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    Can I nit pick something?

    The computer still thinks it's a 5.3, so the fueling calculation will be off for the 6.0 engine size. Smooth that VE out too.

    You could get away much more timing advance at part throttle too and have a smoother transition into boost too.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.