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Thread: L86 cammed 6l80e WOT 1-2 2-3 no shift

  1. #21
    And Don't look at my 1-2 shift RPM that was 2wd and it's spininng even tough is was only 50% into the throttle

  2. #22
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    ok keep me posted on results im start may trial and error later around 6pm central
    RPM OUTLAW

  3. #23
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    Quote Originally Posted by Jonblarc7 View Post
    And Don't look at my 1-2 shift RPM that was 2wd and it's spininng even tough is was only 50% into the throttle
    Any luck
    RPM OUTLAW

  4. #24
    I won?t be able to do it until tomorrow. I had to run down to the lake and pick up the boat. I?ll let you know tomorrow.

  5. #25
    Well I'm closer but still haven't hit over 6050 or so. I have the Blue CAT RPMs set to 6350 but it doesn't make it up to that.

    Another thing in bluecat under lead time. If you leave the weight of the car on the lighter side. Does it give it more lead time to make the shift?


    When I loaded the numbers the first time I forgot to change the weight of the vehicle up from the default 3500 pounds and it shifted gears beautifully. Then when I changed the weight up to 5800 pounds it seem to have a slight pause again. Not bad but it just didn't grab that next gear instantly like before.

    Just playing around with the numbers, when I lowered the weight it seemed to lower the mph. Which to me would seem it's trying to give it more time to make the shift.

    Thoughts????

  6. #26
    Advanced Tuner IARLLC's Avatar
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    An idea here...the rpm fuel cut-off has to predict when you will hit the set limit and it works off of some settings to do that. If the PCM thinks that you might hit the limiter very soon it can preempt by beginning to limit early. This is especially prevalent on the 1-2.

    Under Engine>Fuel>Cutoff,DFCO> left column almost to the bottom you have Acceleration Based>Accel Thresh. I usually reduce that table by 50-80%. Maybe somebody more experienced than me can give better input on that but that is what I have done to get the PCM to allow the motor to blast right up to the shift.

  7. #27
    I will give that a try in the morning thanks

  8. #28
    Couldn't get a clean hit this morning. It's 38 degrees here and raining so it spun through 1st,2nd and 3rd and shifted early because I could give it full throttle without the back trying to step out. I'm going to go out at lunch and try a rolling 4x4 pull and see if it will get traction.

    I removed 70% of the Accel Thresh. I also my saw my in gear fuel cut off is set to 6400 so I bumped that up to 6600.

  9. #29
    I was looking at one of my last logs I posted and comparing it to the tune. It?s commanding the shift on the mph exactly. Then shift a few hundred RPMs later. You think I could just move my Mph up to command the shift later and just leave the rpm the same to give it time to shift.

  10. #30
    Advanced Tuner IARLLC's Avatar
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    Good job logging that.

    Yes. Like I mentioned, it is artwork. GEN3 does not care about the mph at WOT but GEN4 and GEN5 do. But you have to keep both together. As you have seen, either one can cause the shift to happen early or so late that it does not happen at all.

  11. #31
    Well that was a no go.

    I raised the WOT mph 4 and and part throttle 100% 4 mph and blended it down to 75%. It shifted but with a pause. So i bumped the MPH another 3 mph thinking it would give it more time to make a shift. I was wrong be it went to a no shift at WOT.




    Here are the logs and tune


    1-25-20 1.hpl1-25-20 2.hpl1-24-20 BBA_G5MAF_v15 2 MPH UP 3 RPM DOWN 200.hpt

  12. #32
    I?m going to try to make the weight of the truck light on the blue cat tool. It seems to give you more lead time

  13. #33
    Advanced Tuner IARLLC's Avatar
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    42 mph was too much....with shift RPM of 5900? MPH and RPM have to work together.

    That was a 56% increase in WOT shift MPH with a 1% increase in WOT shift RPM. There was 0 chance it could work right.

    I was originally suggesting raising them together. Stock 27 MPH and 5800 RPM x 1.07 is 28.89 MPH (29 is close enough) and 6206 RPM (6200 RPM is close enough). Then test. If that works well you can just see what RPM it yields. If it ends up shifting a little low you can try multiplying your stock numbers SLIGHTLY higher.

    Good idea to use Blue Cat. BC can really help you keep upshift and downshift coordinated, and raise numbers together.

  14. #34
    Ok and thanks for all your help. Man this makes me realize I need to go back and learn how to do percentages all over again.

  15. #35
    So I tried two different tunes

    1. Starting with stock number and raised it 27 x 1.095 = 29.565
    5800 x 1.905 = 6,351

    First gear shifts early because of wheel spin. Second gear no shift. It just hangs right around 6000 until I let off.

    Then I load blue cat numbers shifts set to 6,350. First gear shift early because of wheel spin. I?m ok with that. Second gear shifts with a slight pause but not bad at all. But shifts at 5990. It?s like there is a hard limit somewhere I?m missing. I?ll post the tune again later.

    Right now I?m just over it. I hate not figuring stuff out

  16. #36
    here is the tune from earlier. The Blue Cat tune1-26-20 BBA_G5MAF_v15 1 blue cat weight 3500.hpt

  17. #37
    Advanced Tuner IARLLC's Avatar
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    This tune shows you set WOT 1-2 at 5950 RPM.? I don't get it.

    If stock works right and multiplying by 1.07 won't shift, you must be hitting a limiter.

    Since stock works fine...try multiplying by 1.02 or 1.03. Does that work? Does it get you to about 6000 RPM?

    If going higher than that does not work, you are hitting a limiter.

  18. #38
    I believe one of the earlier tunes I bumped it 1.05 which is 6090 and shifted good. I thing it shifted low 5900. Anything higher than that I start getting a pause or no shift.

    Since last one shifted with a very slight pause 2-3. I went back and lower the 2-3 mph .985 to see if it would get a completely clean shift.

    I just can?t find anything that is limiting me.

  19. #39
    Advanced Tuner IARLLC's Avatar
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    It sure looks like you are being cut off at 6000.

    Engine>Fuel>Cut-off>In Gear has some areas that I am not familiar with...set at 6000. Maybe it would be worth it to raise them and see what happens.

  20. #40
    They where set to 6600 in the tune I posted above and the only I loaded today. It been raining all day so I could make a pull in 2nd that would spin and shift early