Page 3 of 3 FirstFirst 123
Results 21 to 26 of 26

Thread: somewhat sluggish at times

  1. #21
    Lifetime Member
    Join Date
    Dec 2011
    Posts
    284

    Default

    if i remember right, it is only about 5% more then stock
    2008 Chevrolet 3500HD DRW LTZ
    285/75/17 Nitto Dura Grapplers, 4.56 gears, Front and rear ARB lockers, Efi Live tuning by me, Raptor 160 LP, Cognito 4-6 NTB Lift, 4" Exhaust, Built Trans by Mike L.

    2004 LB7 Duramax, EFI Live with DSP5 Tune
    stage 4 SC transmission, 265/70/16 tires

  2. #22
    Lifetime Member
    Join Date
    Dec 2011
    Posts
    284

    Default

    Ok, so i got the blocker plate in. still does it. it seems like it doesn't do it for as long though so it helped but it still has the problem.

    now i am thinking it is just not spooling as fast as it should. any tricks i should try to improve spooling? obviously increasing vane position won't help as the ECM is already doing that. maybe lower timing some?
    2008 Chevrolet 3500HD DRW LTZ
    285/75/17 Nitto Dura Grapplers, 4.56 gears, Front and rear ARB lockers, Efi Live tuning by me, Raptor 160 LP, Cognito 4-6 NTB Lift, 4" Exhaust, Built Trans by Mike L.

    2004 LB7 Duramax, EFI Live with DSP5 Tune
    stage 4 SC transmission, 265/70/16 tires

  3. #23
    Lifetime Member Mitco39's Avatar
    Join Date
    Jan 2009
    Posts
    643

    Default

    Boost leak? Do another log so I can take a look if you want.

  4. #24
    Lifetime Member
    Join Date
    Dec 2011
    Posts
    284

    Default

    ok, i'll do that. any location typical for the LMM that leaks tend to form?

    what's weird is that it only does it about 30~50% of the time. when it doesn't do it it takes off real strong smoke free. when it does do it i can usually lift off of the accelerator and reapply it, the 2nd time it will start to accelerate much quicker with much less smoke and much more boost. this is why i keep coming back to vane position, but i am currently running stock vane table and it still does it so???????
    2008 Chevrolet 3500HD DRW LTZ
    285/75/17 Nitto Dura Grapplers, 4.56 gears, Front and rear ARB lockers, Efi Live tuning by me, Raptor 160 LP, Cognito 4-6 NTB Lift, 4" Exhaust, Built Trans by Mike L.

    2004 LB7 Duramax, EFI Live with DSP5 Tune
    stage 4 SC transmission, 265/70/16 tires

  5. #25
    Lifetime Member
    Join Date
    Dec 2011
    Posts
    284

    Default

    Sorry keeping you waiting. Did a boost leak test and didn't come up with anything. Was pushing it to about 20 psi and could not find any leaks.

    Anything else?
    2008 Chevrolet 3500HD DRW LTZ
    285/75/17 Nitto Dura Grapplers, 4.56 gears, Front and rear ARB lockers, Efi Live tuning by me, Raptor 160 LP, Cognito 4-6 NTB Lift, 4" Exhaust, Built Trans by Mike L.

    2004 LB7 Duramax, EFI Live with DSP5 Tune
    stage 4 SC transmission, 265/70/16 tires

  6. #26
    Lifetime Member
    Join Date
    Dec 2011
    Posts
    284

    Default

    i think i got it figured out.

    i lowered the max vane position at the higher rpm and mm3 range and bam, problem seems to be gone. revs much quicker now without any smoke. i think having the vane closed too much can actually hurt spool. looks like having it closed too much will restrict flow so much that the exhaust velocity falls to the point of not being able to turn the turbine faster. open them up a little until you hit max exhaust speed and that will build boost the fastest.

    i ran around chasing all sorts of things but it was a good learning process

    thanks guys
    2008 Chevrolet 3500HD DRW LTZ
    285/75/17 Nitto Dura Grapplers, 4.56 gears, Front and rear ARB lockers, Efi Live tuning by me, Raptor 160 LP, Cognito 4-6 NTB Lift, 4" Exhaust, Built Trans by Mike L.

    2004 LB7 Duramax, EFI Live with DSP5 Tune
    stage 4 SC transmission, 265/70/16 tires

Page 3 of 3 FirstFirst 123

Similar Threads

  1. Sluggish Truck
    By Chuckels in forum Duramax LB7
    Replies: 2
    Last Post: September 17th, 2012, 11:12 PM
  2. 4l80 shifting sluggish and not shiting at wot
    By Cool28 in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 3
    Last Post: March 15th, 2012, 09:49 AM
  3. Car feels sluggish after MAF removal
    By Alex99 in forum Gen III V8 Specific
    Replies: 3
    Last Post: August 18th, 2009, 03:36 AM
  4. Stock 4L65E sluggish 1-2 shift at light throttle - Dashboard attached
    By pacer265 in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 0
    Last Post: July 12th, 2008, 05:25 PM
  5. Truck feels sluggish at part throttle
    By Aint Skeered in forum General (Petrol, Gas, Ethanol)
    Replies: 0
    Last Post: June 9th, 2007, 04:52 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
  •