Page 4 of 6 FirstFirst ... 23456 LastLast
Results 31 to 40 of 56

Thread: Tool to help tune A4 shift points...

  1. #31
    Lifetime Member EagleMark's Avatar
    Join Date
    Dec 2010
    Posts
    466

    Default

    Have to agree! Used this tool for the first time and the visual is great!

  2. #32
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    For reference:

    PT shift table relationships:

    basic relationships:
    1->2 curve should be above 2->1 curve;
    2->3 curve should be above 3->2 curve;
    3->4 curve should be above 4->3 curve;
    . . .

    additional relationships:
    3->2 curve should be above 1->2 curve;
    4->3 curve should be above 2->3 curve;
    . . .

    this can be summarized as: the curves cannot cross anywhere;

    if they cross anywhere, then you will not be able to predict what gear the TCM selects when the operating point hits the cross.
    This is what post #1 is saying.

  3. #33
    Junior Member
    Join Date
    May 2015
    Posts
    36

    Default

    This old thread and the spreadsheet it contains has really help me to visualize my shift points, and I would like to thank SSpdDmon, joecar and the rest of you! I've been experimenting with the shift points and comparing to stock files and others. I've attached my current version, I'd be interested in any input.
    Attached Files Attached Files

  4. #34
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Quote Originally Posted by Illegal Vette View Post
    This old thread and the spreadsheet it contains has really help me to visualize my shift points, and I would like to thank SSpdDmon, joecar and the rest of you! I've been experimenting with the shift points and comparing to stock files and others. I've attached my current version, I'd be interested in any input.
    Thanks for sharing.

    I opened it in LibreOffice Calc and it looks good

  5. #35
    Junior Member
    Join Date
    May 2015
    Posts
    36

    Default

    Quote Originally Posted by joecar View Post
    Thanks for sharing.

    I opened it in LibreOffice Calc and it looks good
    Thanks for taking the time to look at it, I'm flying by the seat of my pants here and your opinion means a lot!

  6. #36
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Some comments on shift curves:

    - you can space out each shift curve and its corresponding upshift curves so that they have more vertical distance between them (see 2002 Camaro A4 tune file), this will improve drivability (i.e. engine rpm "feel" will better match "urgency" of throttle position; i.e. for these pairs 1->2 and 2->1, 2->3 and 3->2, 3->4 and 4->3; when editing, remember to maintain this relationship:
    PT shift table relationships:

    basic relationships:
    1->2 curve should be above 2->1 curve;
    2->3 curve should be above 3->2 curve;
    3->4 curve should be above 4->3 curve;
    . . .

    additional relationships:
    3->2 curve should be above 1->2 curve;
    4->3 curve should be above 2->3 curve;
    . . .

    this can be summarized as: the curves cannot cross anywhere;

    if they cross anywhere, then you will not be able to predict what gear the TCM selects when the operating point hits the cross.
    - same with TCC apply/release curves, space them out (see 2002 Camaro A4 tune file), driveability will improve.



    Then when done editing, set all the WOT MPH shift parameters to the same values at the 100% columns in the PT shift curves.

  7. #37
    Junior Member
    Join Date
    May 2015
    Posts
    36

    Default

    Quote Originally Posted by joecar View Post
    Some comments on shift curves:

    - you can space out each shift curve and its corresponding upshift curves so that they have more vertical distance between them (see 2002 Camaro A4 tune file), this will improve drivability (i.e. engine rpm "feel" will better match "urgency" of throttle position; i.e. for these pairs 1->2 and 2->1, 2->3 and 3->2, 3->4 and 4->3; when editing, remember to maintain this relationship:


    - same with TCC apply/release curves, space them out (see 2002 Camaro A4 tune file), driveability will improve.



    Then when done editing, set all the WOT MPH shift parameters to the same values at the 100% columns in the PT shift curves.
    Thanks for telling me to match the WOT shifts to the 100% PT shifts. My WOT were a dash higher. It looks to me like my upshift and downshift curves are spaced out like you say, but my TCC apply and release are less so. Is this something I should be looking at?

  8. #38
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    If it's a street car, then you can get muclecar feel if you unlock TCC at low VSS.

  9. #39
    Junior Member
    Join Date
    May 2015
    Posts
    36

    Default

    Quote Originally Posted by joecar View Post
    If it's a street car, then you can get muclecar feel if you unlock TCC at low VSS.
    Thus the 255's in the first 2 cells of 3rd apply and 4th apply on the A4 spreadsheet?

  10. #40
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Quote Originally Posted by Illegal Vette View Post
    Thus the 255's in the first 2 cells of 3rd apply and 4th apply on the A4 spreadsheet?
    I meant push the TCC release curve down further, for example look at 2002 Camaro A4 tune file, the 3rd TCC release and 4th TCC release are fairly flat down low... if your PCM keeps TCC applied on zero throttle, having the 3rd/4th TCC release curves low keeps the TCC applied until car is going too slow for TCC, but while above this it feels like a manual tranmission, and makes engine growl when you release throttle (i.e. musclecar feel).
    Last edited by joecar; May 27th, 2015 at 10:05 PM.

Page 4 of 6 FirstFirst ... 23456 LastLast

Similar Threads

  1. Little help with changing shift points
    By Tarkstoys in forum Allison 5 & 6 Speed
    Replies: 6
    Last Post: June 29th, 2009, 05:54 AM
  2. tuning shift points
    By hot-dog in forum Allison 5 & 6 Speed
    Replies: 3
    Last Post: February 28th, 2009, 07:03 PM
  3. shift points
    By rock04max in forum General
    Replies: 2
    Last Post: December 1st, 2008, 12:09 PM
  4. Help with 80E shift points
    By thunder550 in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 9
    Last Post: May 20th, 2008, 02:08 PM
  5. TCM shift points
    By lakingslayer in forum General (Diesel)
    Replies: 4
    Last Post: March 28th, 2007, 10:09 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •