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Thread: 4l80e upshifting when held in gear

  1. #21
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    Quote Originally Posted by joecar View Post
    Try this (attached).

    You have a shift kit, and you're seeing soft shifts...? If you still get soft shifts with the attached file, then try setting the shift times tables to 0.2 seconds all across.
    I tried your file and it still didn't seem to shift that hard so I went ahead and added the .2 to all three shifts. Should I go up more? The 1-2 seems slightly better, but the 2-3 is still sluggish. The trans is a fresh rebuild, and I had him put a Trans Go HD-2 shift kit in. It shifted great when I first started driving it (about a month ago) and slowly has gotten worse. I really appreciate you guys helping me!
    Attached Files Attached Files

  2. #22
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    Is this in a daily driver, competition vehicle, tow rig ?

    Is your engine tune (VE table) reasonably accurate ?

    How firm do you want the shifts to be ?

    The decline in the shift quality you mentioned could be tune related or mechanical. Is the fluid level correct ? Does the fluid look dark or have a "burnt" smell ?

  3. #23
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    Its a street/strip car, this is a COS5 speed density tune. I'm sure the VE tables are still off. The car idles and cruises at 14.4-1 to 14.7-1 AFR but at WOT is pig rich at 10.1-1.

    How much does the VE tale affect the shift?

  4. #24
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    Take a look at the Desired Shift Time tables and the Base Shift Pressure tables - these reference delivered engine torque.

    Not a big deal if the engine tune is off - just means that as you refine your engine tune, you may need to revisit the transmission tune.

    You never answered how firm you want the shifts ... assuming you want these firm to very firm ?

  5. #25
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    Yes, I would like them very firm. The engine should make about 550-600 RWHP once the tune is correct. I upped the base shift pressure tables 5% (that was the first thing I did). What should I change the desired shift time tables to?

  6. #26
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    I'll try and post a tune for you to try in the next day or so ...

  7. #27
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    Thank you sir, I greatly appreciate the help!

  8. #28
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    Sorry ... forgot to ask ... do you have a switch wired to access the Performance Mode shift pattern ?

    It makes things a little easier if you do ... it lessens the compromise ... a drag strip tune can be difficult to live with on the street, and a street tune may give away a little bit at the strip

  9. #29
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    No, I haven't figured out how to do that. Is that like tow/haul in the trucks? I have wanted to do this but have not had a chance to get there yet.

  10. #30
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    Look at parameter D0409 - you want the "One Switch" option. The good folks at EFILive were nice enough to tell you what PCM pin to wire, and to connect this to ground via a momentary switch.

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