02 8.1 Allison tuning

[6.2 turbo]

I'm tuning this Allison with hptuners,and hate the delay it has for downshifts. I dont know if its hydraulics or electrical. I deleted all tm, and increased line psi via force motor. Upshifts are better,just lags about 10 sec for a kickdown/ passing gear.

 

[THEFERMANATOR]

I'm tuning this Allison with hptuners,and hate the delay it has for downshifts. I dont know if its hydraulics or electrical. I deleted all tm, and increased line psi via force motor. Upshifts are better,just lags about 10 sec for a kickdown/ passing gear.

If it's dropping more than 1 gear, it will take some time. By design, the allison must go through each gear, do it's checks, setup for the next gear, and so on for each shift.

 

[6.2 turbo]

Yea I feal it momentarily shift down one gear ,then another gear. Not sure if many people know this,but for some reason the 02 8.1 tcm has all the regular pressure tables like a 4l80 or 4l60. All the same year Dmax just have the off going and on going. Mine has both. The Allison tuning is new to me,but the 8.1 sure woke up with 35 deg ign timing. And it had a 60 sec delay for pe.

 

[THEFERMANATOR]

There is no adjustable line pressure in the allison until 2011. There is ALOT if tables in there that should not be there, and even more that are mislabled. Be dam certain of what you are changing before touching it. I only make small changes to a handful of tables in them. Learned the expensive way to leave the allison tuning alone

 

[6.2 turbo]

Mine has the force motor table,can't say for sure if I increased the psi or not. It has medium firm shifts ,with no tm.

 

[THEFERMANATOR]

The table might be there, but it doesn't do anything as there is no force motor in a 99-10 allison 1000. And turning off torque management is a quick way to hurt your trans. If you want the trans to shift faster, build it to do so. Electronically modifying an Allison to shift faster/firmer is how you break hard parts. It's a HD truck trans.

 

[6.2 turbo]

I believe there is a bunch of fake tables. looks like its just on/off going thats real,but not sure how far i can go with them. I guess Im just spoiled with the 4l60 and 80 tuning.

 

[THEFERMANATOR]

4l60e/4l80e tuning are completely different. The best advice anybody can give you is to leave the trans tuning alone. This includes the torque reference tables in the engine tuning. Clutch to clutch transmissions should NEVER shift firm/hard, those are from tie-ups, abd that destroys hard parts. More allisons have been hurt from tuning than power I would bet.

 

[6.2 turbo]

Looks like I have to pull the pump , if I want to crank line psi. Eventually l want to swap in a Cummins,so the trans will have to be working better than it is now.

 

[THEFERMANATOR]

Looks like I have to pull the pump , if I want to crank line psi. Eventually l want to swap in a Cummins,so the trans will have to be working better than it is now.

The Allison needs to be built with the right combo of parts for it's intended usage. You can shim the pressure spring, but you're still going to lose 100 psi in lockup if you don't do anything about the knock down. Then you have your trim valves which control the actual on and off going pressure to the clutches. You've got offset apply clutches in the 5 speeds and only 4 C3 clutches stock.

Leave your tuning alone, DO NOT try to make it shift hard, and build it right internally.

 

[2wpuller]

I don't change shift timing at all.i have the torque converter locking up in 2and gear staying locked through all shifts.. Have increased fuel mileage. And transmission staying much cooler without tq.convertor slipping tomuch.