Results 1 to 6 of 6

Thread: Editor showing wrong shift points for ZF8?

  1. #1
    Tuner
    Join Date
    Jul 2019
    Location
    Wilmington, MA, USA
    Posts
    155

    Editor showing wrong shift points for ZF8?

    Okay this is a weird one, wondering if anyone has any thoughts? I'm fooling around with tuning my '12 A4 with 2.0t engine and ZF8 transmission.

    The redline on this engine is around 6200 RPM and when I look at most maps under "shift scheduling", the 6 -> 7 upshift at WOT happens at around that RPM. At least it did until today!
    Looking at most of the aggression-based maps, I now see something like this:
    Trans tuning weirdness.PNG
    Note the highest value in the 6->7 shift column is 4750 RPM... and since 6th gear is 1:1 that equates to an engine RPM of 4750! And that's the main "sport mode" map. In every single aggression-based map I've looked at (0 through 24), 4750 RPM is the highest number I see for upshift from 6th gear. Some of the non-aggression-based maps are the same, a few (25 for example) show numbers going up to 6200 which is more what I'd expect.

    Now here's the thing: this is my *stock* file. It's flagged read-only on disk, I have copies of it in multiple places, I'm 100% sure it has not been edited. I checked a few files from similar cars posted on the forum here and they show the same thing. And I'm 99.99% sure when I last looked at this file a couple of weeks ago it showed more "expected' numbers. I even have a spreadsheet that has a table I copied from this file, it goes up to 6200 as expected.

    I've attached the file in question... does anyone have any idea what's going on here? I've looked at the file with the 4.4.4 release version of VCM editor and the latest beta, the problem exists with both.

    FWIW I have another car with the ZF8 transmission, a 2014 A6. That file does not seem to have the same problem. But I think it's a different variant of the transmisison.
    Attached Files Attached Files

  2. #2
    Tuner in Training
    Join Date
    Sep 2019
    Posts
    36
    Ive never really understood these either. Mainly because its shows lower rpm in lower gears, often irrelevant to TPS. For example if you go full throttle in 3rd, it makes it look like its going to shift at 2,940rpm, obviously thats not right.

  3. #3
    Advanced Tuner
    Join Date
    Sep 2019
    Location
    ON, Canada
    Posts
    346
    Is it not measured in transmission output shaft speed?

  4. #4
    Tuner
    Join Date
    Jul 2019
    Location
    Wilmington, MA, USA
    Posts
    155
    It is, but on this transmission 6th gear is 1:1 ratio so output shaft speed = input shaft speed. And input shaft speed = engine RPM minus a little for torque converter slip.

    For comparison, here is the same table from my other car, which has the same transmisison (except for newer software) and a 6300 RPM redline:
    Trans tuning no weirdness.PNG

    Looking at the two, I'm realizing there seem to be only two columns that are out of whack: the 6->7 upshift, and the 7->6 downshift. The other columns appear correct. And it's not every row either... just the ones above about 50% throttle. It's like the values in those columns have been capped at 4750... very strange.
    Last edited by ELaw; 11-29-2019 at 07:42 PM.

  5. #5
    Tuner
    Join Date
    Jul 2019
    Location
    Wilmington, MA, USA
    Posts
    155
    Well the support people got back to me and they can't find anything wrong! I guess I'm probably remembering wrong and those were the shift points all along. They're weird, but if the RPM was higher it would probably be above the car's top speed capability so maybe that's the reason for the weirdness.

  6. #6
    Quote Originally Posted by ELaw View Post
    Well the support people got back to me and they can't find anything wrong! I guess I'm probably remembering wrong and those were the shift points all along. They're weird, but if the RPM was higher it would probably be above the car's top speed capability so maybe that's the reason for the weirdness.
    my 2011 b8 has the same values as your pic in the first post, i was noticing differences between my tables and Perry's he has a b8.5. Have never had my car WOT in 6th gear to see when it shifts. But have to take my daughter down to A&M Friday so maybe i can get a 2fer (scare the hell out of her and see when it shifts)
    Last edited by bb-tt; 01-01-2020 at 04:07 PM.