Results 1 to 8 of 8

Thread: Sky Red Line 2.0 L4 - 5L40E

  1. #1
    Tuner in Training
    Join Date
    Sep 2015
    Posts
    20

    Sky Red Line 2.0 L4 - 5L40E

    I've attempted to write calibration for a T68/5L40E combo (stock 2008 Saturn Sky Red Line Automatic Transmission.)

    My goal was to move shift points forward under WOT. I've made a number of calibration changes, none of them appear to have any effect, I ultimately replicated the same 'Speed' and 'RPM' settings for all shift pattern and state tables (so *all* tables for Normal, Pattern A, Pattern B, Hot, Hot Engine, 'WOT' and 'Part Throttle'.)

    Here are the shift points I'm attempting to configure:

    Shift RPM
    1->2 5300
    2->3 5600
    3->4 6100

    Shift Speed
    1->2 30
    2->3 50
    3->4 76
    2->1 20
    3->2 40
    4->3 65

    Attached is a tune file with the trans. calibration as described above, as well as a log file showing the shifts are still occurring at Speeds and RPMs higher than what I've specified. I understand both Speed and RPM (and other factors) are taken into account when shifting.

    AM I missing something, or is this not actually working correctly?

    I've noticed when I flash the TCC calibration the vehicle anti-theft dash indicator light comes on at the end of flash. Car runs without any problems. Not sure if this is an indication that the flash is not succeeding. Not sure how to verify the flash is being written (suppose I could try doing a 'read-entire' when I'm back in my garage?)

    Has anyone else successfully reprogrammed shift points on a 2008 Sky RL Automatic Transmission?

    Thanks in advance!

    TUNE: !2008-SKY-RL-AUTO-TRANSONLY-READENTIRE-[24237654].hpt

    LOG: v3-013.hpl (see 7:59:19 for sample WOT through 1st, 2nd and 3rd gears.)
    Last edited by wilson0x4d; 03-07-2016 at 07:29 PM. Reason: replaced attachment with "read entire" of T68, shows correct tune settings

  2. #2
    Tuner in Training
    Join Date
    Sep 2015
    Posts
    20
    I have performed a read-entire of the T68 (TCM-only read) and compared it to the tune file I've been working from, VCM Editor shows no differences ("compare log" is empty, visual check shows what I read from the T68 is what I last wrote to it.)

    I must be failing to understand something, I could use some advice and/or wild guesses at this point.

  3. #3
    Advanced Tuner
    Join Date
    Mar 2014
    Posts
    231
    It's been a while since I've tuned my trans on my 09 Redline but it does work. If I remember correctly, it took several pulls to get the PCM to shift where I programmed it so if you're still on that same tune, log it again to see how it is responding now.

    I use a spreadsheet that calculates speed and rpm for each gear and I'll typically set the speed in the tune roughly 5 mph less than what is shown on the spreadsheet so that the speed is met first so the shift happens when the rpm is hit if that makes sense. If the speed and rpm are too close together, you could miss the shift.

  4. #4
    Tuner in Training
    Join Date
    Sep 2015
    Posts
    20
    Quote Originally Posted by JimmyS View Post
    It's been a while since I've tuned my trans on my 09 Redline but it does work. If I remember correctly, it took several pulls to get the PCM to shift where I programmed it so if you're still on that same tune, log it again to see how it is responding now.

    I use a spreadsheet that calculates speed and rpm for each gear and I'll typically set the speed in the tune roughly 5 mph less than what is shown on the spreadsheet so that the speed is met first so the shift happens when the rpm is hit if that makes sense. If the speed and rpm are too close together, you could miss the shift.
    I've left the tune in place for a couple days now with no obvious change in WOT Shift behavior.

    I also disconnected battery leads yesterday to let caps/settings purge to see if that would coerce a change, still no obvious change.

    I'll try setting lower Speed values when I'm back in the garage. I wish I had thought of that before posting, hopefully it's that simple.

    Thanks!

  5. #5
    Advanced Tuner
    Join Date
    Mar 2014
    Posts
    231
    The spreadsheet I use shows 32.96mph at 5300 rpm, 53.90mph at 5600rpm and 81.09mph at 6100rpm so your 3 to 4 shift should be okay but you probably need to drop your 1-2 and 2-3 by another 2 mph and see how it works. I will try to look at your tune to see if I notice anything else.

  6. #6
    Tuner in Training
    Join Date
    Sep 2015
    Posts
    20
    Confirmed, 'Speed' values were still too high. It was that simple.

    Moving my shift Speeds down ~5mph results in "reasonably close" shifts for in 1->2 (5300-5600rpm avg) and 2->3 (5600-5900rpm avg).. RPM is what seems to determine my shift points now. *thumbsup*

    I'll continue playing with Speeds and RPMs at this point until I find the sweet spot for my current tune, after some careful logging and testing I noticed there is slight delay between actual Speed and the Speed the vehicle is reporting. I suspect a similar delay exists in reading/responding to RPM change, since there's a "fairly consistent" delay of ~100-150 rpm before the shift occurs.

    Either way, mystery solved,

    Thanks again!

  7. #7
    Advanced Tuner
    Join Date
    Mar 2014
    Posts
    231
    Glad to hear that worked. I've heard or read somewhere that the speedo's in our cars are a bit on the slow side.

    While you're tuning the trans, if you want quicker shifts, you can start by taking the stock shift time settings and cut them in half. I've cut mine by quite a bit more than half and haven't had any problems.

  8. #8
    I came across your post about changing the shift points on the 5L40E. I've been working on my trans as well, setting it up more as a sport mode all the time. Right now every WOT upshift is at 6000. However, I noticed that 1>2 and 2>3 really end up with falling boost because they hit the gear at around 4500 (peak boost) and decrease on the way to 6000.

    I was thinking the car might be quicker upshifting sooner, similar to your posted shift points. Any 0-60 benefit by shifting sooner?

    Thanks!


    Shift RPM
    1->2 5300
    2->3 5600
    3->4 6100