Hp tuners, torque management clarity

[SpareParts]

I bought mine used at 230k Now its at 238K and as far as i know the original trans. It does have a JMBX torque convertor in it for now.
Carfax shows 3 trans flushes. Last one at 190K. I changed filter and all fluid at about 235K. No bad stuff in the pan.
From 217K to 230 when i bought it there are no records.
If your fluid is good and the pan has no bad stuff in it i would not be afraid to tune it some.

 

[LSxBakakos]

I bought mine used at 230k Now its at 238K and as far as i know the original trans. It does have a JMBX torque convertor in it for now.
Carfax shows 3 trans flushes. Last one at 190K. I changed filter and all fluid at about 235K. No bad stuff in the pan.
From 217K to 230 when i bought it there are no records.
If your fluid is good and the pan has no bad stuff in it i would not be afraid to tune it some.

Im with spareparts on this one.

In my opinion a fresh trans will live a longer life with properly set shift timing, pressures etc and an old clapped out trans will have more life if its already on its way

The reason is, pressure will put a greater load on the clutches that are there and in theory will apply and release at a quicker rate. Then theres the other area of fatigue which is the line pressure loss upon converter lockup, not to mention how you can map how it applies under the max line pressure table.

Unfortunately no amount of tuning will save a worn pr valve, boost valve, failing circuits within the trans etc but if the trans is in good health, I see it extending the life of whats there

Theres a video I saw I think on hptuners talking about changing the adaptives for lost clutch material. So id imagine if you go in with the intention of cleaning things up vs a hot trans tune for the $150 in credits you can probably get a decent bit more life out of a stocker.

Then theres the double edged sword, well all be changing out values if theres a built trans in play, and removing electronic line pressure for mechanical lol. I wish I could get this thing to shift how my old 60 did or my built allison, but im 90% sure theres no defueling in that

 

[mikez71]

Log your spark timing when you reduce torque management numbers.
Does it reduce the timing dip? (I haven't tried it, been busy nursing my gmt-800..)

I've been able to reduce that delay in the 1-2 shift by copying parts of later models torque adders map. Also tweaked myself the 2-3 torque adders to eliminate a big delay in the 2-3 shift that occurs when TCC is disabled in 3rd gear. I think the stock torque adders have a delay there to smooth TCC engagement.. That's my theory anyways..

Not saying that is the only or best way to do it, but another option.
(that requires more time since you are tweaking a map vs just a single number)

 

[Marky Dissod]

Best way to do it is so that the driver and (maybe front rider?) barely notice lazy gentle non-enthusiastic light part-throttle shifts;
if they do notice them, they should not take any longer to complete, and may be accompanied by a VERY gentle bump.

As throttle angle increases, shifts should get quicker and may be accompanied by discrete (NOT discreet) bumps.

Wear is not completely avoidable, but GM was willing to increase wear a bit to improve NVH,
whereas a tuned vehicle should kinaesthetically confirm each shift more quickly than GM OE without any net increase in wear (except maybe to the tires).

 

[mikez71]

I like smooth full throttle shifts too.. But I definitely like reducing shift times as much as possible.. (smoother when you don't give it too much time to coastdown between shifts..)

 

[Marky Dissod]

I like smooth full throttle shifts too, but I definitely like reducing shift times as much as possible. (smoother when you don't give it too much time to coastdown between shifts.)

Slightly increasing line pressures and slightly quickening shift times is basically the goal.

 

[LSxBakakos]

Log your spark timing when you reduce torque management numbers.
Does it reduce the timing dip? (I haven't tried it, been busy nursing my gmt-800..)

I've been able to reduce that delay in the 1-2 shift by copying parts of later models torque adders map. Also tweaked myself the 2-3 torque adders to eliminate a big delay in the 2-3 shift that occurs when TCC is disabled in 3rd gear. I think the stock torque adders have a delay there to smooth TCC engagement.. That's my theory anyways..

Not saying that is the only or best way to do it, but another option.
(that requires more time since you are tweaking a map vs just a single number)

If i remember correctly the spark timing is the only engine tm left thats not completley disabled. Ill for sure have to look into it and lot it more. Do you recall what you set your torque adders to? And im unlocked TC 1-3 which im sure is softening the hit too

As far as shift feel I definitely like feeling it, but do like seeing it as fast as possible

 

[mikez71]

If i remember correctly the spark timing is the only engine tm left thats not completley disabled. Ill for sure have to look into it and lot it more. Do you recall what you set your torque adders to?

Good to know, all I remember is there is big dip in timing every shift, and I wonder how and how much that can be reduced safely. Heard often that engine TM can be disabled, but you want to keep some trans TM..

I'll take some screenshots of my Torque Adders later tonight.

But so far noticed if I lowered the whole map, it would shift too abruptly at low throttles.
But if you look at 2-3 TA in 2018 truck tunes, the 2000-3000 rpm positive torque adder cells are faster, which feels smoother to me.

That's the basis of what I've done so far to torque adders, plus my own massaging of the 2-3 torque adders to get rid of hesitation/delay (at modest throttle angles) But I also lowered my 2-3 upshift schedule for smoothness. Figure we're turning higher rpm's unlocked vs locked, but I kept having this hiccup feeling at lower throttles in my 2-3 shift.. But have been wondering if I can raise the shift speeds back up if I just speed up the shift time..
I suspect the stock 2-3 schedule and Torque Adders are increased to accomodate TC lockup that tends to happen in that gear/throttle area..

Full throttle I'm pretty much stock, I don't like feeling the bumps, prefer smooth power delivery. But to that end I have not experimented much there. Some changes at WOT caused little hiccups. Not sure if I was asking it to shift faster than it could or what the deal was... Maybe I needed that pressure increase so it can hold the faster shift...

 

[LSxBakakos]

Good to know, all I remember is there is big dip in timing every shift, and I wonder how and how much that can be reduced safely. Heard often that engine TM can be disabled, but you want to keep some trans TM..

I'll take some screenshots of my Torque Adders later tonight.

But so far noticed if I lowered the whole map, it would shift too abruptly at low throttles. But if you look at 2018 truck tunes, the 1750-3000 rpm positive torque adder cells shift faster and smoother.

That's the basis of what I've done so far to torque adders, plus my own massaging of the 2-3 torque adders to get rid of hesitation/delay (at modest throttle angles) But I also lowered my 2-3 upshift schedule for smoothness. Figure we're turning higher rpm's unlocked vs locked) I suspect the stock schedule is raised and torque adder times increased to accomodate TC lockup that tends to happen in that area..

Full throttle I'm pretty much stock, I don't like feeling the bumps, prefer smooth power delivery. But to that end I have not experimented much there. Some changes at WOT caused little hiccups. Not sure if I was asking it to shift faster than it could or what the deal was... Maybe I needed that pressure increase so it can hold the faster shift...

From what ive gathered off the hptuners video the # the guy likes to use is 140psi for line pressure, at at 150, tahoe ive also been tuning is 140 and more aggressive. Pressure does have to be able to support shift times which the fastest a stock 6l80 can shift is .20.

Originally I had started out by multiplying .80 on shift timing for a 20% reduction ghen bottom right 6 tabs i put to .20. After I kept increasing until I went .20 across the entire board(hated the moosh 1-2 shift) a different tune i did messing with the inertia factor seemed odd/wasnt a fan of it.

Ive also been told engine tm should be deleted fully but for some odd reason any 6l80e tuning says to keep some enabled. I may mess with it lol

Im just curious where both of our files are or if any images I have show where mine are set just so both of us can reference. Page 1 does have my YouTube shorts on WOT shifts without log

 

[mikez71]

Yea there's a lot of variables to test!
I did bump inertia factor for a couple low rpm / low torque cells in my 1-2 shift.. I think it helped this tiny lurch at very light throttle..

All city driving, so my tuning has really just been trying to refine daily driving behavior.

Here's my current torque adders.
I tend to adjust in .0125 increments, but possibly some areas could use better resolution...

One thing about the Torque Adders, there was someone else on hpt.forum that was complaining about their 2-3 shift delay.
I shared with him what I did, but when I saw his tune, all his values were lower already! (Like a stock map with all values reduced)
Still he decided to reshape his map like mine by reducing his values further, and claimed it cured his delay also. ?
So I'm not sure what the deal is, maybe as it shifts, it's picking starting and ending cells, and using the slope as an adjusting factor?
Or maybe he was just used to much faster shifting.. I don't really know..

 

[LSxBakakos]

Yea there's a lof of variables to test!
I did bump inertia factor for a couple low rpm / low torque cells in my 1-2 shift.. I think it helped this tiny lurch at very light throttle..

All city driving, so my tuning has really just been trying to refine daily driving behavior.

Here's my current torque adders.
I tend to adjust in .0125 increments, but possibly some areas could use better resolution...

One interesting story about the Torque Adders, there was someone else on hpt.forum that was complaining about the 2-3 shift delay.
I shared with him what I did, but when I saw his tune, all his values were lower already! (Like a stock map with all values reduced)
Still he decided to reshape his map like mine by reducing his values further, and claimed it cured his delay also. ?
So I'm not sure what the deal is, maybe as it shifts, it's picking a point to another point on the map and using the slope as an adjusting factor?
Or maybe he was just used to much faster shifting, and the slow spot was relatively slow for him. I don't really know..
View attachment 484341

Im going to have to look at mine and compare so that maybe both of us have a better understanding/can see what the other has changed, id rather not give you false info lol. I know with the changes ive made mine has no delay on 1-2,2-3,3-4 whether its part throttle or WOT.

As much as I hate computers this has been quite the learning experience

 

[SpareParts]

Mine seems to take to long for the 1-2 shift around 3/4 throttle.
Been thinking of dropping the TCU and changing the pressure switch diaphragms in case they are torn.

 

[dkad260]

Mine seems to take to long for the 1-2 shift around 3/4 throttle.

Funny you mention that...I was looking into mine to what seemed like a slightly longer 1-2 shift 2 days ago....likely not what you are experiencing but I was thinking on using HPT to modify it.

I changed my trans fluid and filter on Sunday, with the intake boot off, I cleaned the MAF meter. Once I left on the test drive, I noticed a delayed 1-2 and also a very slight delay but not a flare in the 2-3. After a few miles the 2-3 was good but the 1-2 was slightly delayed.

I didn't think too much about it until I remembered my impala with the torn intake boot and it was getting some unmetered air past the MAF. The Impala had noticeable flare in the 1-2 and 2-3 until I replaced the boot.

So I think by cleaning the MAF, I changed the perceived engine load to the computer which may have lowered my shift pressures....along with maybe the new fluid but not sure which change did what.

I cleared the TCM and later just did a NEG terminal disconnect for an hour. After a couple miles it seems to shift ok again. I hooked up the Tech 2 and noticed the 1-2 averages .45 sec and the rest seem to average around .25 sec give or take.

After about 20 min of driving all the shifts were consistent, with the 1-2 about .2 seconds longer than the rest of the gears. This feels the same as it was before I worked on it, but now I'm hyper-focused on it now and wondering if my 1-2 shift time is normal, and if I could tune out another tenth or so. No more perceived delay, just wondering why the 1-2 is noticeably longer.

Anything to reduce wear but not make it hit each gear too hard.

 

[mikez71]

Mine seems to take to long for the 1-2 shift around 3/4 throttle.
Been thinking of dropping the TCU and changing the pressure switch diaphragms in case they are torn.

Good point! I have wondered if changes I make are compensating for transmission issues..
For me, 1-2 shift was slow around 1/4 throttle, but the reduced cells in torque adders helped there (2500 rpm)..
I have made no other changes to shifting other than schedule and torque adders.
Take that back, I did also use the later inertia factors, but the changes seem to be some reduction in the higher rpms..
For the 2-3 delay I felt, it was also around 1/4 throttle.. (2500 - 3000 rpms)

So I think by cleaning the MAF, I changed the perceived engine load to the computer which may have lowered my shift pressures....along with maybe the new fluid but not sure which change did what.

Another good point! Although I would think cleaning the MAF should let it read more air, increasing shift pressures.
For my 4l80, when I installed a new MAF that read higher flow numbers at WOT, the PCS line pressure seemed to go from 70% to 80%.
(old one threw a code, LTFT was 25%, new MAF it's 10%. Old MAF read 230g/sec at WOT, new MAF now reads 280g/sec)

Hope you guys are remembering to reset adaptives.
Initially I didn't do that, seemed fine. But one day I finally reset it again, and ended up with a huge delay in my 2-3 shift..
So now I reset them everytime..

 

[SpareParts]

I have not reset adaptive at all. Maybe a good idea?

 

[mikez71]

Do it!
Curious if you will feel a change since its never been reset. I do the top 3 resets in VCM Scanner just to be sure..

 

[mikez71]

Just wanted to add a couple more tweaks..

If you look at my 1-2 & 2-3 torque adders, the negative-torque/low-rpm cells have INCREASED times.
(inspired by later model tunes, which feel increased too much)
This cures a lift-throttle-upshift clunk, that I usually feel when going downhill and lifting at low throttles.

Also, disabling neutral skip DOWNSHIFT.
For the 5-2 and 6-3 downshifts, it eliminates that feeling of long pause, then hard drop into gear..
Although it downshifts twice, you don't notice the first downshift. Smoother, and I doubt it's any slower..
I'm not sure why the factory programmed that option....? Skip UPSHIFT I can understand.

Also just remembered, the 6.2 6l80 tune is quite a bit different than the 5.3 6l80 tune...

 

[dkad260]

I would think cleaning the MAF should let it read more air, increasing shift pressures.

It would read more air but at a lower throttle position. I'm not sure where the TPS comes into play with regards to line pressure, etc over other sensors like MAP and MAF. The Impala had a noticeable change in trans behavior with the unmetered air removed.

 

[LSxBakakos]

I have not reset adaptive at all. Maybe a good idea?

Ill try to cover the other replies later but any time trans related tables have changed you are supposed to reset the top 3 adaptives from top to bottom per hptuners video directly, so just an fyi

 

[SpareParts]

Did not know that but i do now! I did reset them. Do they relearn fast?
My scanner only has the option to "Rest transmission adaptation" I assume it resets them all?
I drove it about 5 miles running to the parts store and back Different for sure. No more 1-2 slow shifts! It did seem to be shifting odd with some shifts so i assume it's going through the relearn process still.