Adjusting Allison Shift Times

[Sparky8370]

Has anybody played with this? Is there a minimum time to keep? What are the risks involved in shortening the times? Why do the desired shift time throttle adjust values start to increase in the upper tps% on the 3>4 and 4>5 shifts? Is there a reason not to adjust these values to shorten the shift times?

[stacks04]

i know on the 3-4 up shift the on coming and off going clutch packs are right near each other and they tend to tie up under higher hp combo's. i believe they must have saw this from the factory and to prevent it they just added a few milliseconds to the shifts. as the power goes up the tcm can't prevent it even with the added timing. it is not a pleasent feeling the 3-4 shift. that is also why they have the defuel integrated into the calibration.

[Sparky8370]

i know on the 3-4 up shift the on coming and off going clutch packs are right near each other and they tend to tie up under higher hp combo's. i believe they must have saw this from the factory and to prevent it they just added a few milliseconds to the shifts. as the power goes up the tcm can't prevent it even with the added timing. it is not a pleasent feeling the 3-4 shift. that is also why they have the defuel integrated into the calibration.

Shouldn't this be exactly the opposite? Shouldn't they be making the shift times shorter to prevent slippage? From the reading that I have done on this subject, it appears that the reasoning behind it was to make the shifts softer. I want to make them shorter so there isn't as much chance to slip.

[horsehaulin]

Send me your ECM tune and I will make some changes to it that makes it shift like a ATS Co-pilot.

You dont want to shorten the shift as you could bind the shifting and ruin the build! I have a built trans and still shifted the same, thats the function of the adaptive shifting.

Send me the basics of your truck like built trans, engine mods and I will help to adjust the tune to your trans and get it to the point that you are happy about the way it shifts.

Tony
Armdist@yahoo.com

[stacks04]

Shouldn't this be exactly the opposite? Shouldn't they be making the shift times shorter to prevent slippage? From the reading that I have done on this subject, it appears that the reasoning behind it was to make the shifts softer. I want to make them shorter so there isn't as much chance to slip.

if you tune to defuel more than you can make them shorter. if not the more power the more of a chance you'll have a tie up. heva you driven one with the defuel turned off via the tcm tune. the 3-4 shift is a hard parts breaking shift with the stock shift timing. i can only imagine what it would be like in a higher hp truck with a quicker shift. the allison was not designed to shift like a turbo 350. adding the trans-go and or co-pilot only adds to the problem by making it shift quicker. the trans go does it hydraulic, and the co pilot does this electronically.

[Sparky8370]

Duramaxtuner (Nick) has made me a DSP5 tune. I've made some tunes already myself. One tune I made I pretty much copied and it was only supposed to be a 100hp tune, but I added timing to it and reduced the defuel. I limped my tranny on that one. I made a more conservative tune and didn't reduce the defuel as much and it's a really good tune. I just figured I'd adjust this too so it didn't have as much of a chance to slip. I'm not too worried about breaking hard parts because it's not to bad right now.

Oh, and I think you can disable adaptive shifting by reducing the shift times to zero, or at least I read that about other gm trannies.

[horsehaulin]

Your trans and engine have two differant tunes! The TCM holds the tune for the trans and the ECM holds the tune for the engine. When you tune the engine you are not tuning the trans what so ever, so be careful about tuning the engine as you can put more power to the ground without getting things right in the trans.

The best thing to do is to use the adaptive learning to your advantage, not shut it off. It is there so you dont shift like a old TH350 with a shift kit all day. I have a built trans and it still shifts nice and smooth like the factory build, except I have more clutches and a Trans Go. The adaptive learning/shifting is there to save the trans, use it.

Tony

[Sparky8370]

Your trans and engine have two differant tunes! The TCM holds the tune for the trans and the ECM holds the tune for the engine. When you tune the engine you are not tuning the trans what so ever, so be careful about tuning the engine as you can put more power to the ground without getting things right in the trans.

The best thing to do is to use the adaptive learning to your advantage, not shut it off. It is there so you dont shift like a old TH350 with a shift kit all day. I have a built trans and it still shifts nice and smooth like the factory build, except I have more clutches and a Trans Go. The adaptive learning/shifting is there to save the trans, use it.

Tony

Yes I know, but the torque reduction is in the ecm. The only tables in the tcm I was interested in adjusting are the shift times.

[The Neens]

Yes I know, but the torque reduction is in the ecm.

What about D5194,5195,5196,5197 in the TCM?

[stacks04]

torque reduction come from the trans, yes it is adjusted in the ecm but the requests are made from the tcm. if you limit it or turn it off that you do it in the trans. before the tables became available in the tcm you had to best match the torque limited injection quantity to your shift points and make it work. as far as clutches go there is very limited slip that occurs under power during a shift. the factory as far as i am concerned used the defuel to prevent parts breaking from the amount of torque they have stock. the only shift i'd worry about slipping under power is the 4-5. and it is much more relevant to discuss the slipping while under power in a gear. namely 5th gear.

the slip during a shift over the long term will not hurt you nearly as bad as the cost of fixing a shift tie up because your timing was off.

[stacks04]

Your trans and engine have two differant tunes! The TCM holds the tune for the trans and the ECM holds the tune for the engine. When you tune the engine you are not tuning the trans what so ever, so be careful about tuning the engine as you can put more power to the ground without getting things right in the trans.

The best thing to do is to use the adaptive learning to your advantage, not shut it off. It is there so you dont shift like a old TH350 with a shift kit all day. I have a built trans and it still shifts nice and smooth like the factory build, except I have more clutches and a Trans Go. The adaptive learning/shifting is there to save the trans, use it.

Tony


not sure what you mean by getting it right in the trans. having it rebuilt with a performance setup or by tuning. if by tuning than that is not right. very few people go in and touch the trans tuning. very few variables and a lot of money there. you can run a pretty good size tune on the tcm tune that is there. not the parts inside, but the tune will adapt to it.

[horsehaulin]

The trans tune should match the engine tune in the Torque tables to a point. If you have a stock trans then you have no need to alter the TCM, but if you have upgraded the internals than working with the TCM tune can make the trans better. Some buy a ATS Co-pilot to get a race shift, but one could do the same with out the extra cost and it is true tuning, not fooling with false signals.

Tony

[Cougar281]

How would you adjust the torque table to match? The TCM tune has the table using RPM and TPS, but the ECM is using RPM and fuel (mm3).

[Sparky8370]

What about D5194,5195,5196,5197 in the TCM?
I don't have those tables in my tcm. Mine is an 01.
I adjusted B0741

If the ECM is trying to limit engine torque then this table will define the commanded injection quantity value based on the torque value the ECM is trying to limit to.
This table is responsible for the 'de-fuel' effect during transmission shifts as the ECM attempts to limit engine torque as requested by the TCM.

I'm glad there is actually interest in this topic. There doesn't seem to be any info available and I like the discussion on it.

[Cougar281]

Originally Posted by The Neens
What about D5194,5195,5196,5197 in the TCM?

on mine (04 LLY OS), D5194 & D5195 are for the 8.1L gasser, I'm not sure how D5196 relates to the ECM tune since the TCM uses RPM & TP, wheras the ECM uses RPM and mm3, and D5197 will prevent the TCM from ever requesting defuel.

Sparky, they should be in your tune if you're using a current relase. I just opened a few of the 01 TCM OS tunes that I have and they all had those tables. They're all under "Torque Control".

[The Neens]

torque reduction come from the trans, yes it is adjusted in the ecm but the requests are made from the tcm.

You're absolutely right, I read that incorrectly...




Sparky, they should be in your tune if you're using a current relase. I just opened a few of the 01 TCM OS tunes that I have and they all had those tables. They're all under "Torque Control".

Dave, I remove/max out those tables in the TCM tune and control the defuel in the ECM tune...I've run it that way for several thousand miles with no known ill-effects...Seems to work with my truck...

Try at your own risk...

[Cougar281]

You're absolutely right, I read that incorrectly...



Dave, I remove/max out those tables in the TCM tune and control the defuel in the ECM tune...I've run it that way for several thousand miles with no known ill-effects...Seems to work with my truck...

Try at your own risk...

I'm confused.... 5194 & 5195 don't apply to our trucks, so that leaves 5196 & 5197. If you Change 5197 to "Torque Limit Req Disable", the TCM won't even request defuel, so nothing in the ECM will even attempt defuel because the TCM didn't request it. That leaves 5196. I guess if you max that one out, it more or less won't defuel?

I was running with 5197 set to "Torque Limit Req Disable" and for the most part it shifted quite nice, but Mike L kinda worried me about a tie up. :eek:

I'm not too worried about clutch wear, as I think I could replace the clutches with what's in there without much trouble (I'd order replacement sets from Eric), but I AM worried about a tie up. Don't feel like picking pieces of my transmission up off the ground!

[Sparky8370]

on mine (04 LLY OS), D5194 & D5195 are for the 8.1L gasser, I'm not sure how D5196 relates to the ECM tune since the TCM uses RPM & TP, wheras the ECM uses RPM and mm3, and D5197 will prevent the TCM from ever requesting defuel.

Sparky, they should be in your tune if you're using a current relase. I just opened a few of the 01 TCM OS tunes that I have and they all had those tables. They're all under "Torque Control".
No I don't have any of those. What do you mean by latest release, latest efi or an updated tcm tune? This is the stock tcm tune out of my truck.

[Cougar281]

They're in your tune. What version are you running? I've got 7.5.4. I know D5197 came out some time after January. The others may have as well.

[Sparky8370]

I have 7.5.3 I've been looking to see when .4 comes out but haven't seen it.

[Sparky8370]

I've got them now. Thanks for the cals cougar, but they were the same I had. I found 7.5.4 and now I have it.

[stacks04]

the ecm torque limited injection quantity tables are only for defuel when the tcm request it. if you never touch the tcm and do lots of logging and run your logs against the tune tables, with the right changes you all but eliminate the defuel effect. thats how it was done long before the tcm tables came out in the beta release. now that the we have the ability to turn off the torque control there is no need to tune the torque tables in the ecm tune. the same table is in the tcm tune if you so choose to have the defuel left on. then you can change the defuel "effect" by adjusting the values in the 5196 table.

[The Neens]

I'm confused.... 5194 & 5195 don't apply to our trucks, so that leaves 5196 & 5197. If you Change 5197 to "Torque Limit Req Disable", the TCM won't even request defuel, so nothing in the ECM will even attempt defuel because the TCM didn't request it. That leaves 5196. I guess if you max that one out, it more or less won't defuel?

The more current updates have these tables...

There are other ways to control the "defuel" aside from the torque limiting tables...Compare B0727 to B0741/1102 in this tune...