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Thread: WOT Shift, 1-2, 2-3

  1. #1
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    Default WOT Shift, 1-2, 2-3

    I've been tuning the WOT shifts on a T42 / 4L70E.

    For instance, in the 1-2 upshift WOT tables (D1011 and D1021), which does it use?

    I had D1011 set to 43 MPH and D1021 set to 5800. I hit the rev limiter at 6000, which I don't understand. I was at about 41 mph.

    What is the logic here? Is it 'AND', 'OR', or 'HIGHER OF THE TWO' ?

  2. #2
    Joe (Moderator) joecar's Avatar
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    The logic is AND.

    This is the same problem seen with LS1/LS6 PCM's...

    The PCM somehow misses when to shift...

    you may have to set one of those parameters low (e.g. set to 30 MPH), and fine tune the other one (e.g. start at 5000 RPM, test it, bump it a little, test it...) to where it shift's where you want it to.
    Last edited by joecar; February 25th, 2008 at 04:51 AM. Reason: I couldn't understand what i wrote

  3. #3
    Lifetime Member N0DIH's Avatar
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    Which rules first? rpm or speed? I tune my OBD1 and it doesn't go by rpm, speed only.

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    Its kinda whenever both get hit. i.e. set upshift rpm to 6100rpm and speed to 40mph, hit 40mph first and then when the rpms hit 6100 it shifts. At least thats how my 4L60E works...
    ~Erik~
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    Lifetime Member N0DIH's Avatar
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    So if I set rpm to say 2000 rpm, and shift mph to 41, it would pass 2000 rpm and then shift at the moment I get to 41?

    Not really sure what the value having both and an AND logic on it.

    IF rpm = x AND mph = y THEN shift
    ELSE wait and keep revving
    IF hits rev limiter, oh well!

    Correct?

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    Quote Originally Posted by N0DIH
    IF rpm = x AND mph = y THEN shift
    ELSE wait and keep revving
    IF hits rev limiter, oh well!

    Correct?
    Yep, that's correct. And always take TCCSlip into account when setting the MPH value.

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    Yes, which is the problem I hit.

    So, i created a spreadsheet which calculated this all out, and subtracted about 15% from anticipated MPH. This seems to work well. I will share when I get home.

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    Actually, I have access to it from work.
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  9. #9
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by arubenstein
    Yes, which is the problem I hit.

    So, i created a spreadsheet which calculated this all out, and subtracted about 15% from anticipated MPH. This seems to work well. I will share when I get home.
    What are your current WOT MPH/RPM points set to, and what MPH/RPM are you actually shifting at...?

    Do you have a stall converter...?

  10. #10
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    Don't know yet. Just loaded this in this morning and will do some scanning tonight.

    The transmission was done by a local guy, it has a Vigilante Triple Disc 2500.

    I will report back my findings later.

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