Page 2 of 2 FirstFirst 12
Results 11 to 18 of 18

Thread: 2-3 shuttle shift fix

  1. #11
    Lifetime Member DoghouseDiesel's Avatar
    Join Date
    Dec 2009
    Posts
    1,017

    Default

    Lowering the TTVA value will cause it to shift earlier, raising the value will delay the shifts. The TTVA angle effects the boost pressure and boost valve, which effects line pressure. Drag the TTVA angle out for too long and you're causing the line pressure to not rise as you're increasing the load....not a good thing to do. You also have a few other factors that messing with the TTVA can effect and if they're not adjusted correctly you get some weird up/down shifts and also a bunch converter locking/unlocking.

    Being that the 48 doesn't have great line pressure as it is, unless the trans is modified, I DO NOT recommend lowering the TTVA angles for the sake of stretching out shift points. Making the shift points occur at higher RPM's is no issue, as you're increasing TTVA angle and therefore line pressure, which is a good thing. But again, you have to take a few other things into account otherwise you'll still get some weird tranny behavior.

    On mine, with the single 88, I need the shift points much higher in the RPM range to stay on top of it. This is what mine looks like (minus the actual values and scale). Just for reference, this shifts at 3900 RPM's at WOT. You also have to look at your 3-4 up and down shift points and your converter lock and unlock, otherwise it'll be all over the place. You have a bit of room to increase the max TTVA angle also, 50* is not it's max travel. If you set it too high, you'll know it, it'll toss a code for the TTVA being stuck. That's how you know you've reached the max angle for your particular trans.

    Click image for larger version. 

Name:	TTVA Race.jpg 
Views:	365 
Size:	114.8 KB 
ID:	15686
    Last edited by DoghouseDiesel; August 18th, 2013 at 11:23 AM.

    1207 HP / 1612 TQ

  2. #12
    Senior Member
    Join Date
    Dec 2007
    Posts
    133

    Default

    Quote Originally Posted by DoghouseDiesel View Post
    You have a bit of room to increase the max TTVA angle also, 50* is not it's max travel. If you set it too high, you'll know it, it'll toss a code for the TTVA being stuck. That's how you know you've reached the max angle for your particular trans.

    Click image for larger version. 

Name:	TTVA Race.jpg 
Views:	365 
Size:	114.8 KB 
ID:	15686
    What are the pros and cons to raising it past 50* to the highest possible setting?
    06 Laramie 3500 QC SB 4x4 - Full billet Auto by DTT, HE351/S475 twins, EFI live, lots of custom goodies....

    07 6.2L Yukon Denali - CAI, CAT delete, self tuned with EFI Live

    03 Trailblazer 4.2L I6 - CAI, custom exhaust, EFI live

    2010 Laramie 3500 CC LB 4x4 - H&S, DPF delete, waiting for EFI Live.....

  3. #13
    Lifetime Member DoghouseDiesel's Avatar
    Join Date
    Dec 2009
    Posts
    1,017

    Default

    Depends on how you're using the truck and what is done to the trans.

    1207 HP / 1612 TQ

  4. #14
    Senior Member
    Join Date
    Dec 2007
    Posts
    133

    Default

    Quote Originally Posted by DoghouseDiesel View Post
    Depends on how you're using the truck and what is done to the trans.
    well in my case, i drive it like i stole it more often than i should. as for the transmission, i asked DTT to give me the works in hopes of handling the abuse. lol
    06 Laramie 3500 QC SB 4x4 - Full billet Auto by DTT, HE351/S475 twins, EFI live, lots of custom goodies....

    07 6.2L Yukon Denali - CAI, CAT delete, self tuned with EFI Live

    03 Trailblazer 4.2L I6 - CAI, custom exhaust, EFI live

    2010 Laramie 3500 CC LB 4x4 - H&S, DPF delete, waiting for EFI Live.....

  5. #15
    Senior Member
    Join Date
    Dec 2007
    Posts
    133

    Default

    any drawback to increasing the minimum TTVA angle above 3*?
    06 Laramie 3500 QC SB 4x4 - Full billet Auto by DTT, HE351/S475 twins, EFI live, lots of custom goodies....

    07 6.2L Yukon Denali - CAI, CAT delete, self tuned with EFI Live

    03 Trailblazer 4.2L I6 - CAI, custom exhaust, EFI live

    2010 Laramie 3500 CC LB 4x4 - H&S, DPF delete, waiting for EFI Live.....

  6. #16
    Lifetime Member 2007 5.9's Avatar
    Join Date
    Nov 2010
    Posts
    1,835

    Default 2-3 shuttle shift fix

    Quote Originally Posted by skneeland View Post
    any drawback to increasing the minimum TTVA angle above 3*?
    My first value is 15*
    Les Szmidt
    2007 5.9 Dodge Ram
    2014 Ram 3500 Aisin tuning Emissions Equipped
    EFI Live Cummins BETA Tester
    Silver Bullet Tuning
    silverbullettuning@gmail.com
    www.youtube.com/ljszmidt
    http://www.facebook.com/SilverBulletTuninig

  7. #17
    Senior Member
    Join Date
    Dec 2007
    Posts
    133

    Default

    Quote Originally Posted by 2007 5.9 View Post
    My first value is 15*
    interesting...good to know.

    i have been driving myself mad for the last week trying to totally eliminate the 2-3-2 shuttle. respanning and remapping both the TTVA and gov pressure maps. I have it to the point that its almost gone, except it will do one downshift to 2nd between 50-60kph, BUT only if i lift my foot off the pedal while in this range. No problems below 50, and if i accelerate right through to 60 it wont happen either.
    06 Laramie 3500 QC SB 4x4 - Full billet Auto by DTT, HE351/S475 twins, EFI live, lots of custom goodies....

    07 6.2L Yukon Denali - CAI, CAT delete, self tuned with EFI Live

    03 Trailblazer 4.2L I6 - CAI, custom exhaust, EFI live

    2010 Laramie 3500 CC LB 4x4 - H&S, DPF delete, waiting for EFI Live.....

  8. #18
    Senior Member
    Join Date
    Dec 2007
    Posts
    133

    Default

    ok, someone wiser have a look and tell me whats wrong.

    at around 740 frames and 940 frames it does that odd downshift i described earlier

    between 550 and 1350 frames although the log says my desired pressure and actual pressures are in order, they are way out to lunch compared to my table (actual commanded pressure in this area is 150 to 300kPa) ?!?

    the builder wants me to drop the pan and make some mods to the VB, but i cant help but wonder if there is more out of wack here?
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Trans log.jpg 
Views:	200 
Size:	272.9 KB 
ID:	15902  
    06 Laramie 3500 QC SB 4x4 - Full billet Auto by DTT, HE351/S475 twins, EFI live, lots of custom goodies....

    07 6.2L Yukon Denali - CAI, CAT delete, self tuned with EFI Live

    03 Trailblazer 4.2L I6 - CAI, custom exhaust, EFI live

    2010 Laramie 3500 CC LB 4x4 - H&S, DPF delete, waiting for EFI Live.....

Page 2 of 2 FirstFirst 12

Similar Threads

  1. No Shift time adjustment in new 6L80E OS? Adjusting shift times in Torque Model
    By Protec in forum 6 speed/8 speed RWD/FWD Transmission Tuning (incl T43, T76, T87)
    Replies: 2
    Last Post: February 13th, 2013, 09:34 AM
  2. How do I fix this
    By wadesns in forum General
    Replies: 2
    Last Post: March 28th, 2012, 11:18 PM
  3. rpm cut off comes up before the 2>3 shift , wont shift
    By Eric in forum Gen III V8 Specific
    Replies: 7
    Last Post: June 6th, 2011, 08:58 AM
  4. How can I fix this?
    By odd boy in forum General
    Replies: 5
    Last Post: June 14th, 2008, 05:28 PM
  5. Disable adaptive shift learning after Shift Kit Install
    By BlackGMC in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 3
    Last Post: January 24th, 2008, 04:49 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
  •