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Thread: T43/E38 6L90 Shift points change

  1. #11
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    Default T43/E38 6L90 Shift points change

    Quote Originally Posted by 55chevdelray View Post
    Thanks. Thanks for the encouragement. I was able to download both controller files (E38 & T43) and saved them to my computer. I wasn't sure about what version I should be using. I downloaded the V7.5 and the current updates and also downloaded the V8 with current firmware updates as well. I had some initial problems opening the E38 but found the ZIP file, to address that problem. I'll need to determine the best shift points to set into my trans controller. I haven't found any spreadsheets that help to determine optimum shift points. Any knowledge of where I might find one. I found one yesterday, but it was in metric and I'd like one in MPH. Thanks again, it is a bit of the forest before the trees for me right now.
    Please read the entire post before attempting any changes. I am assuming your truck is in sound mechanical condition and that you are using a good bit of common sense when testing so you don't tear your truck up if you made a mistake. This is a guide that I follow for my trucks, make changes at YOUR OWN RISK. If you are not comfortable tuning your transmission consider buying a tune from a tuner.

    Happy reading


    What I've been doing on my personal truck (ls1B = 05 5.3 and 4L65, so it's gonna be a little different cause I only have 4 gears to work with, but not too different)

    1. Correct you speedo for any tire change. Verify the speedo output from the ECM matches the TCM speedo output matches your speedometer. You'll have to make a couple datalogs to verify this. If you need help with that let us know.

    (The following is for up shifts)
    2. Set your WOT shift points and copy those values to your part throttle shift tables for throttle positions 65% and up

    3. Determine what speeds you want your truck to shift at when your driving easy (less than 30% throttle position) I tuned my moms 6L80 to always keep the rpms above 1500 after the shift. Just drive it in manual mode and take notes at what speeds you want it to shift at.

    4. Go to your part throttle tables and at approx 15% throttle, set the values to the what you liked from step 3. Then for 0% throttle, subtract 2-3 mph from that value and for ~30% throttle add 2-3 mph to that value. Highlight the cells from 0-30% inclusive and select the linear smooth button from the toolbar. You should see the graph become a nice smooth line. Or you can do that manually by picking numbers.

    5. Highlight starting with the 30% throttle cell you changed to the 65% throttle cell you changed and click the linear smooth button again to make a nice straight line. You can massage the corners (no more than 2 points) so you have nice smooth transitions in the graph.

    6. Determine what gears you want the torque converter to lockup in. I did gears 4-6 in my moms and 2-4 in mine. Locate the TCC folder and find the TCC apply speeds. For 4th gear TCC apply speeds, copy the entire 3->4 part throttle shift table to the 4th gear TCC apply speed table and then multiply every value by 1.05. That will let the truck shift then lockup the converter. Some people prefer to simply add 2mph instead of multiply by 1.05. It's all personal preference of how quick you want it to lockup. Then repeat that process for the other gears. 4->5 copies to 5th gear apply speeds. 5->6 to 6th gear apply speeds, and so on.

    7. (Downshifts) for simplicity sake, start with WOT. Determine what speeds to downshift at. ***make sure your downshift speed is LOWER than your up shift speed, or you can create the shuttle shift where your truck can't decide what gear to be in*** one guide is for the (example) 3->4 WOT up shift, subtract 5mph and that is you 4->3 downshift speed. Set all your WOT downshift speeds similar to that process.

    8. Copy the WOT downshift speed to the appropriate part throttle downshift table at throttle positions greater than 85-90%.

    9. This is where it can get confusing... For the 4->3 downshift, go to the 3->4 up shift tables and highlight the cells that have speeds LOWER than your WOT downshift speed for the 4->3 shift. Copy those cells from the 3->4 table to the 4->3 downshift table so that the last cell you highlighted lands at the 85-90% throttle position. This means that there will be cells at the top of that table that are unchanged.

    10. For the cells that were left unchanged after that last copy event, copy the 0% throttle position up shift speed and subtract ~3-5 mph and set that as your 0% downshift speed. Highlight from 0% to the "corner" on the graph where you shift points start climbing rapidly and click the linear smooth button. That will give you a good starting point for your downshift tables. You can massage the values where you want it to shift sooner or lug harder.

    11. TCC release speeds. (Torque converter unlock) for (example) 4th gear release speeds, copy the entire 4->3 part throttle downshift table to the 4th gear release speeds and either multiply all values by 1.05 or add 2mph. Do this for your other gears. (5->4 downshift to 5th gear release and so on) This will let the converter unlock right before the shift for smoother downshifts.

    That's the basic process I follow. For your 6th gear downshift since that's your highway gear you will most likely have to adjust the values so that it will lug more and not shift so quick on a hill. I set my 75% throttle downshift speed to 75mph and smooth the graph from there. That's by no means a final shift table, but it will get you close enough you can simply tweak values and get there.

    Use caution, go slow. It takes me an hour to rebuild all my tables for my 4L65. Take notes of what tables you've changed, are changing, and have left to change cause its easy to get lost and copy to the wrong one or miss one.
    Last edited by Wheelz; May 21st, 2013 at 05:05 AM.
    14 GMC Sierra
    5.3L CC SB 4x4
    Basic tuning....

  2. #12
    Junior Member 55chevdelray's Avatar
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    Quote Originally Posted by Wheelz View Post
    Please read the entire post before attempting any changes. I am assuming your truck is in sound mechanical condition and that you are using a good bit of common sense when testing so you don't tear your truck up if you made a mistake. This is a guide that I follow for my trucks, make changes at YOUR OWN RISK. If you are not comfortable tuning your transmission consider buying a tune from a tuner.

    Happy reading


    What I've been doing on my personal truck (ls1B = 05 5.3 and 4L65, so it's gonna be a little different cause I only have 4 gears to work with, but not too different)

    1. Correct you speedo for any tire change. Verify the speedo output from the ECM matches the TCM speedo output matches your speedometer. You'll have to make a couple datalogs to verify this. If you need help with that let us know.

    (The following is for up shifts)
    2. Set your WOT shift points and copy those values to your part throttle shift tables for throttle positions 65% and up

    3. Determine what speeds you want your truck to shift at when your driving easy (less than 30% throttle position) I tuned my moms 6L80 to always keep the rpms above 1500 after the shift. Just drive it in manual mode and take notes at what speeds you want it to shift at.

    4. Go to your part throttle tables and at approx 15% throttle, set the values to the what you liked from step 3. Then for 0% throttle, subtract 2-3 mph from that value and for ~30% throttle add 2-3 mph to that value. Highlight the cells from 0-30% inclusive and select the linear smooth button from the toolbar. You should see the graph become a nice smooth line. Or you can do that manually by picking numbers.

    5. Highlight starting with the 30% throttle cell you changed to the 65% throttle cell you changed and click the linear smooth button again to make a nice straight line. You can massage the corners (no more than 2 points) so you have nice smooth transitions in the graph.

    6. Determine what gears you want the torque converter to lockup in. I did gears 4-6 in my moms and 2-4 in mine. Locate the TCC folder and find the TCC apply speeds. For 4th gear TCC apply speeds, copy the entire 3->4 part throttle shift table to the 4th gear TCC apply speed table and then multiply every value by 1.05. That will let the truck shift then lockup the converter. Some people prefer to simply add 2mph instead of multiply by 1.05. It's all personal preference of how quick you want it to lockup. Then repeat that process for the other gears. 4->5 copies to 5th gear apply speeds. 5->6 to 6th gear apply speeds, and so on.

    7. (Downshifts) for simplicity sake, start with WOT. Determine what speeds to downshift at. ***make sure your downshift speed is LOWER than your up shift speed, or you can create the shuttle shift where your truck can't decide what gear to be in*** one guide is for the (example) 3->4 WOT up shift, subtract 5mph and that is you 4->3 downshift speed. Set all your WOT downshift speeds similar to that process.

    8. Copy the WOT downshift speed to the appropriate part throttle downshift table at throttle positions greater than 85-90%.

    9. This is where it can get confusing... For the 4->3 downshift, go to the 3->4 up shift tables and highlight the cells that have speeds LOWER than your WOT downshift speed for the 4->3 shift. Copy those cells from the 3->4 table to the 4->3 downshift table so that the last cell you highlighted lands at the 85-90% throttle position. This means that there will be cells at the top of that table that are unchanged.

    10. For the cells that were left unchanged after that last copy event, copy the 0% throttle position up shift speed and subtract ~3-5 mph and set that as your 0% downshift speed. Highlight from 0% to the "corner" on the graph where you shift points start climbing rapidly and click the linear smooth button. That will give you a good starting point for your downshift tables. You can massage the values where you want it to shift sooner or lug harder.

    11. TCC release speeds. (Torque converter unlock) for (example) 4th gear release speeds, copy the entire 4->3 part throttle downshift table to the 4th gear release speeds and either multiply all values by 1.05 or add 2mph. Do this for your other gears. (5->4 downshift to 5th gear release and so on) This will let the converter unlock right before the shift for smoother downshifts.

    That's the basic process I follow. For your 6th gear downshift since that's your highway gear you will most likely have to adjust the values so that it will lug more and not shift so quick on a hill. I set my 75% throttle downshift speed to 75mph and smooth the graph from there. That's by no means a final shift table, but it will get you close enough you can simply tweak values and get there.

    Use caution, go slow. It takes me an hour to rebuild all my tables for my 4L65. Take notes of what tables you've changed, are changing, and have left to change cause its easy to get lost and copy to the wrong one or miss one.
    Thanks, I'll give it a go, and get back if I have questions. The tranny has only 2000 miles on it and came out of a 3/4 ton pickup. I put it into my 55 Chevrolet.
    Brian
    EFI Live V2
    55 Chevy with C4 Corvette Suspension
    LS376/480 (E38) and 6L90(T43)
    My Project: http://www.picturetrail.com/sfx/albu...r/55chevdelray

  3. #13
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    Default T43/E38 6L90 Shift points change

    No prob. Ill post up a tune so you can see what I'm trying to say, when I stop for the night.
    14 GMC Sierra
    5.3L CC SB 4x4
    Basic tuning....

  4. #14
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by 55chevdelray View Post
    How do I post the file?
    Start typing a response then click Go Advanced, then click Manage Attachments.

  5. #15
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    Sorry it took so long. here is my latest tune of my 4L65. But you can see what my shift curves look like

    LS1B_0008.ctz
    14 GMC Sierra
    5.3L CC SB 4x4
    Basic tuning....

  6. #16
    Junior Member 55chevdelray's Avatar
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    Finally getting somewhat comfortable with tuning. Made some changes to my TCM shift points. Seems the T43 reacts to speed rather than rpm for shift points.
    Brian
    EFI Live V2
    55 Chevy with C4 Corvette Suspension
    LS376/480 (E38) and 6L90(T43)
    My Project: http://www.picturetrail.com/sfx/albu...r/55chevdelray

  7. #17
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    Hi I have a question how can you tell if engine and transmission are working correctly together?

  8. #18
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    Hi I am looking for help someone who knows transmission 6 L90 and e38 controller and see tables to make sure they are correct in working together. Can you help.
    I have one file that is good and one that is not and want to transfer.
    The one that is not shifting right is when it's uphill with Ac on and heavy load. I am in California.

  9. #19
    Junior Member 55chevdelray's Avatar
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    Quote Originally Posted by sb1111 View Post
    Hi I am looking for help someone who knows transmission 6 L90 and e38 controller and see tables to make sure they are correct in working together. Can you help.
    I have one file that is good and one that is not and want to transfer.
    The one that is not shifting right is when it's uphill with Ac on and heavy load. I am in California.
    Did you ever get this figured out?
    Brian
    EFI Live V2
    55 Chevy with C4 Corvette Suspension
    LS376/480 (E38) and 6L90(T43)
    My Project: http://www.picturetrail.com/sfx/albu...r/55chevdelray

  10. #20
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by sb1111 View Post
    Hi I am looking for help someone who knows transmission 6 L90 and e38 controller and see tables to make sure they are correct in working together. Can you help.
    I have one file that is good and one that is not and want to transfer.
    The one that is not shifting right is when it's uphill with Ac on and heavy load. I am in California.
    I somehow missed your post back in January...

    Post both TCM files, and the ECM file.

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