Page 1 of 2 12 LastLast
Results 1 to 10 of 16

Thread: Programming a T43 to work in an offroad buggy with 39" tires

  1. #1
    Junior Member
    Join Date
    Mar 2010
    Posts
    46

    Default Programming a T43 to work in an offroad buggy with 39" tires

    I have a L92 thats stroked to 427ci from a 2007 escalade or denali and then its maded to a 6l80e trans. this is in an offroad buggy built for offroad racing and rockcrawling.

    I need to program the transmission so that it shifts at higher rpms. currently (due to the tire size being way off I assume) the trans shifts from one gear to the next at very low rpm even at WOT.

    I'm using a mast motorsports ECM but it has a cable to send all the necessary data to the T43 so it will shift.

    I have EFI live 7.5 and 8.0 on the CD/hardware I purchased from Blackbear Performance and I'm not sure which version to use since 8.0 almost seems like incomplete software currently but perhaps it needs an update. I purchased the software in February and the license card has a Jan 26th date.

    Any help in how to accomplish this would be very much appreciated. I am a total newbie with EFI live other than watching Justin Gadberry at Black Bear tune my 8.1L Suburban. I'm in CT and he's in VA so I'd like to be able to tune the transmission (and my Suburban for that matter) with the software.

    Currently I'm going through the scanning tutorial provided with the software.

    Thank You

  2. #2
    Lifetime Member
    Join Date
    Jul 2004
    Posts
    640

    Default

    For the moment, use V7.5 for scan and tune. Use V8.0 for upgrading and configuration of the handheld.

    Ira

  3. #3
    Lifetime Member
    Join Date
    Mar 2006
    Posts
    4,935

    Default

    Also, download the latest V7.5 and V8 software from the www.efilive.com homepage. Lots of new updates in the latest stuff.
    ~Erik~
    2013 Sonic RS Manual - 1.4L I4T E78, tuned, turbo mods, etc.
    2008 TrailBlazer SS 3SS AWD Summit White - LS2 E67/T42, bolt ons, suspension, etc.
    2002 Chevy TrailBlazer LT 4X4 Summit White - 4.2L I6 P10, lifted, wheels, etc.

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

    Default

    Post your T43 file... people will ask: what axle ratio and transfer case ratio do you have...?

  5. #5
    Lifetime Member
    Join Date
    Dec 2007
    Posts
    1,143

    Default

    in the T43 cal there is a speedo section. H0101, 102, 103, 136. PLus a speedo calculator.

    Have a shot at getting these lined up with your diff and tyres.

  6. #6
    Junior Member
    Join Date
    Mar 2010
    Posts
    46

    Default

    My axles are 4.56:1 and the transfer case is either 1:1(probably obvious in hi range) or 3:1. I'm not too concerned about shifting gears when I am in low range, eventually I'd like to have some type of manual control over doing say a 1-2 shift but for now first gear is fine.

    In high range is where I'm really concerned about getting the trans shifting right. I will post the T43 tune file once I pickup the buggy today and get efilive hooked up.

    I have 7.5 off the CD and currently with web updates I am at 7.5.6 update 110. I will check to see if there is something even more recent.

    Thanks to everyone for the responses so far.

  7. #7
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Updates see here.

    V7.5.6.112 (scantool/tunetool)
    V8.1.2.92 (2.6.33 for V2).

  8. #8
    Junior Member
    Join Date
    Mar 2010
    Posts
    46

    Default

    I downloaded the latest 112 update and I have not forgotten about this thread. I was out pre-running for the May 7th race this past weekend and the transmission up shifts really early around 2k rpm. also it does not downshift when you decelerate into a turn which then means it isn't in the right gear to punch it going through the turn and out.

    Unfortunately I'm on a business trip right now so I can't post the stock tune or start to figure out how to adjust the shift points. When I get home Thursday I hope to post up more information and get advice from the experts because I really need the transmission shifting better before this race.

    Thanks!

  9. #9
    Lifetime Member swingtan's Avatar
    Join Date
    Jul 2007
    Posts
    1,589

    Default

    I'm thinking out loud a little here...

    Following on from GMH308,

    In the T43 ( like most ) there are tables to set

    • the number of speed sensor pulses per KM / Mile {H0101}
    • the number of speed sensor pulses per revolution { H0102}
    • Final Drive Ratio {H0103}
    • Tire revolutions per KM /Mile {H0104}


    Depending on the original vehicle, ( and working in metric.... ) these setting could be...

    • {H0101}: 49258
    • {H0102}: 36
    • {H0103}: 2.92
    • {H0104}: 478.0


    This would be for a stock sedan with 19" wheels. The thing is that the figure for {H0104} appears to be a factor of 10 out on what it should be ( it should be 4780 ). Working backward through the figures shows {H0101} is also a factor of 10 out, so at least it's consistent.

    In theory, {H0102} should net need to change, so you would want to look at the other three. The easiest would be {H0103}, which should be set to 4.53, but would only be correct for high range. In low the TCM will not know you have a 13.59:1 final drive ratio.

    The next thing is that the 39" tires have a rolling diameter of maybe 900mm. This would give a Rev/KM value of 1111. This is what {H0104} should be. Then calculating back for {H0101} you get 181200.

    So to allow the TCM to know what is going on ( in Hi range ) the values should be something like...

    • {H0101}: 181200
    • {H0102}: 36
    • {H0103}: 4.53
    • {H0104}: 1111


    The only thing that doesn't make sense ATM is that with your current set up, assuming stock values for the speedo, it would shift late.....

    So I wonder if the TCM is getting confused and up-shifting early because the RPM / speed correlation is way off. Maybe the TCM is up-shifting because it sees high RPM, but is reading a VSS that is much lower than it thinks it should be.

    An idea to see what is happening would be to log the TCM parameters. There is a chance that it's getting bad data as well. for a start, I'd log the following from the T43....

    • Engine RPM
    • VSS
    • ACCEP


    this would at least let you know what the TCM thinks is occurring.

    Simon.

  10. #10
    New Member
    Join Date
    Apr 2010
    Posts
    1

    Default

    I'm the original poster's co-driver. I figured I would post a couple pics to help stimulate the discussion. I know Dave is out of town on business and will be more active on the thread here shortly when he is back working the buggy i think tomorrow.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IMAG0209.jpg 
Views:	274 
Size:	391.3 KB 
ID:	7773   Click image for larger version. 

Name:	IMAG0213.jpg 
Views:	270 
Size:	537.2 KB 
ID:	7774  

Page 1 of 2 12 LastLast

Similar Threads

  1. "Paste & multiply" doesn't work?
    By Garry in forum General (Petrol, Gas, Ethanol)
    Replies: 13
    Last Post: December 20th, 2013, 12:12 PM
  2. EFILive "Classic"/"Legacy"/"Historic"?
    By emarkay in forum FlashScan V2
    Replies: 6
    Last Post: November 2nd, 2008, 01:48 AM
  3. "PCM is in an Unkown State" & "Reflash Failed"
    By foxySS in forum General (Petrol, Gas, Ethanol)
    Replies: 5
    Last Post: September 8th, 2006, 11:53 AM
  4. How does the "checksum" checker work?
    By Redline Motorsports in forum General (Petrol, Gas, Ethanol)
    Replies: 1
    Last Post: January 2nd, 2006, 04:31 PM
  5. Tuning for new larger tires. Need Help
    By jamesbond2509 in forum General (Petrol, Gas, Ethanol)
    Replies: 3
    Last Post: October 30th, 2005, 01:11 PM

Posting Permissions

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