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  1. #1
    Super Moderator Six_Shooter's Avatar
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    Transmission tuning...

    I'm about ready to try some transmission tuning.

    The main patient is using a '7060 and a 4L80E, but another patient is using a '7427, and a 4L60E.

    Looking at the $85 XDF there are two tables for shift, "Normal Mode Upshift/Downshift Vs. MPH Vs. TPS" and "Performance Mode Upshift/Downshift Vs. MPH Vs. TPS." I would suspect these two tables are what is the main control for when the tranny shifts, based on TPS, but the numbers in th etable are not defined as something that I can relate to. When I first looked at them I though that a higher number would mean delayed or higher RPM shift, but then looking deeper into the tables, the performance mode table has some lower numbers than the normal mode table.

    I'm going to try and find some information I vaguely recall seeing a few years ago, but in the mean time, anything you have, lets get it in this thread. :D
    The man who says something is impossible, is usually interrupted by the man doing it.

  2. #2
    RIP EagleMark's Avatar
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    I'm not sure how it works in $85. But in $EE LT1 4L60e has those 2 tables and performance mode is activated by a switch only available in Trans Am. It is a button on shifter but it can be added to Camaro, Corvette and B body LT1 with a switch that sends a ground to wire on PCM. I'll include the writeup in a txt file that says it may be possible in others.

    If all paremeters are in the $85 XDF the one I found to make a big differance was shift times. If you look at shift times in performance mode they were all 0, but in regular mode had varied times. I had changed the times to 0 and was a much firmer shift and tranny temps went down. Could actually feel shifts like a truck or performance car instead of one big slush...

    Changing shift points MPH can be very tricky. I tried this and thought was good till I datalooged and saw at highway speeds trans was shifting 3/4/3/4/3/4 so I turned and went home and got a tranny hot error code... to many other varibles to just make one table change I found. I don't know if it's possible for you to take entire trans table from a $EE but I ended up starting with a caddy 1994 V4P RPO towing option trans bin and it was great start, had raised shift points and capable of downshifting when WOT at speed where stock bin would not. That and the shift times were all I needed to turn the Buick Roadmaster big slush box to an actual trans shifting gears at higher RPM like a performance car or truck feel.
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    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
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  3. #3
    Super Moderator dave w's Avatar
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    I was given this Excel spreadsheet, I hope helps.

    dave w
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  4. #4
    RIP EagleMark's Avatar
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    Wow that is cool! There is one in the $EE info thread for doing speedo changes for gears and tires for LT1 but no where near as detailed as this.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  5. #5
    RIP EagleMark's Avatar
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    When looking through the $85 yesterday I found some hacks and will attach one here. It's BAMY, Line 4051 starts transmission and the performance stuff starts at line 4474.

    I'm trying to figure out the flags section of that XDF. Some are easy to find but others seem to be wrong, while many are missing...

    EDIT: Removed hack as it was not $85 but $D8...

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  6. #6
    RIP EagleMark's Avatar
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    It looks like all the hacks in zip marked $85 are $D8 so not sure this is applicable. No wonder I can't figure out error codes... anyone have a $85 hack ?

    BCC Find shows BAMY to be same PCM...

    EDIT: I do have 2 $85 hacks if you need them.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

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