Not your normal shift defuel question
- Thread starter dylon333
- Start date
im confused on what you are asking. are you trying to get the ecm to pull more fuel as it shifts or not pull as much as it shifts?
What do you shifts feel like now and have you logged the truck currently?
What do you shifts feel like now and have you logged the truck currently?
How would you do to make it Defuel less so it's not as aggressive?
Would you do the reverse to make it defuel more and make it more aggressive?
Trying to get truck to defuel more. Shifts feel a little soft. Trans is not slipping yet.
Little back story might make things make more sense. The truck was tuned when I bought it. I didn't like the tuning, and had efi live and wanted to play with it myself. Then wanted to try the early lock up tune that's posted on here some where not realizing the trans had been tuned also. Before I played with trans tunes it Defueled so much that it wouldn't hold a burn out through the shift. Which I also didn't like. But now am just trying to make the truck be reliable and last so ideas of what I like have changed.
Little back story might make things make more sense. The truck was tuned when I bought it. I didn't like the tuning, and had efi live and wanted to play with it myself. Then wanted to try the early lock up tune that's posted on here some where not realizing the trans had been tuned also. Before I played with trans tunes it Defueled so much that it wouldn't hold a burn out through the shift. Which I also didn't like. But now am just trying to make the truck be reliable and last so ideas of what I like have changed.
Put a stock trans/stock engine tune in and let the trans learn. It should shift smooth and have no hiccups through the shifts. This is what you want as you build power in. You should by no means be touching the defuel tables unless you absolutely know what you are playing with and have tuning dialed. By the looks of what you have done prior and are playing with now, you still have lots of work in the tuning area.
Good shifts are also dependent on how the tune is built even with stock defuel in place. You can get crap shifts like bad defuel or not enough if the tune is not built well.
I watched a post on facebook blow up cause a dude in a dually couldn’t get his truck to spin into 2nd gear as he tried a burnout from a roll. No one had a clue about defuel on there. They all wanted their junk to just spin through the gears. If you don’t understand the operation of the trans and how it works, you will never get why defuel must be there. I’m glad you changed your idea of what you want in a burnout lol
Good shifts are also dependent on how the tune is built even with stock defuel in place. You can get crap shifts like bad defuel or not enough if the tune is not built well.
I watched a post on facebook blow up cause a dude in a dually couldn’t get his truck to spin into 2nd gear as he tried a burnout from a roll. No one had a clue about defuel on there. They all wanted their junk to just spin through the gears. If you don’t understand the operation of the trans and how it works, you will never get why defuel must be there. I’m glad you changed your idea of what you want in a burnout lol
My tunes seem to run great, really clean, 18mpg average on fuel. I just wanted to get that pause between the gears back that was there before. Ha ha not so worried about burnouts either. Building a new house and don't have the time or funds for the truck to be down so thought if the trans De fueled a little more I'd be helping to keep the trans alive
Forgot to change that as I've been through this already. The trans is supposed to be rebuilt with "better clutches shift kit, bigger converter" per P.o. But the receipt got lost between him showing to me and me taking possession of the truck so I'm not exactly sure what's been done to it
But fixing the signature now
But fixing the signature now
I think your splitting hairs. If the shifts are smooth and nothing feels rough or hits into gear, you are on a good road. When you feel that hit, that’s when it’s an issue
Ok I'll leave it alone then I guess. It shifts smooth. No hiccups or anything like that. I'd still like to figure out the trans tuning but there's so little information other then don't do it you'll **** it up. But man the shirts sure seemed more firm like a built trans when I bought it. But he'll maybe there was a problem in the trans tune and that wasn't good
The problem is we don’t have enough tables to accurately tune the trans for shifts. There is just enough to destroy stuff but not make it work. We are missing ALOT. Most you can do is tune in shift points, make different gear starts and change tc lock up/unlock.
Firm shifts do not indicate a well built Allison. Forget your daddy's built 400 turbo. We are a lot smarter than that now. Smooth shifts is the new black.:thumb::cool2:
I come from the Cummins world if your trans is soft you better start pricing a trans haha. As far as learning how the trans tuning works when though everyone says you'll screw it up. I still want to learn how it works. People told me I was stupid for buying efi live and doing my own tuning 5 yrs ago that I should just buy tunes. But here I am have learned a lot about tuning still have plenty to learn but have tuned bunch of trucks with no issue. Kind of same thing on the trans. Even if I don't use it is still like to learn how it works. I've figured out how to change lock up points but that's where I stopped
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You are aware how to torque match your tcm torque control table to your pedal torque desired table in the ecm?? Look at how gm did this with the stock tunes and it will make sense, it's really straight forward.
To add more defuel, lower the values slightly in the torque control area in your tcm tune. Example; if your at 1400rpms, 8% pedal, you might be at 200ftlbs. If you go into the fuel rate table 200ftlbs might line up to be 25mm3 at 1400rpms. If you want it to defuel to 15mm3 at this time during a shift, find the torque value that 15mm3 would be and enter it into the correlating matched cell in the tcm tune. All numbers were off the top of head, not actual.
To add more defuel, lower the values slightly in the torque control area in your tcm tune. Example; if your at 1400rpms, 8% pedal, you might be at 200ftlbs. If you go into the fuel rate table 200ftlbs might line up to be 25mm3 at 1400rpms. If you want it to defuel to 15mm3 at this time during a shift, find the torque value that 15mm3 would be and enter it into the correlating matched cell in the tcm tune. All numbers were off the top of head, not actual.
Op Read this post again! It not about learning how to tune the trans or how it works. We don’t have the proper tables to be tuning the trans outside shift points etc.
Tuning the engine is a walk in the park compared to the trans. You pretty much can’t destroy the engine in the short term by making a mistake. The trans on the other hand you can.
So if you can’t pay don’t play.
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I guess what I'm not getting is why the previous trans tune shifted the way it did and it changed soon as I changed the tune. Of course the original tune was locked So I can't read it's it pulled it out but can't get it to open the file says I don't have the permission needed
i think we all made that pretty clear in here as to the very possible reasons "why". it could be a shit load of different reasons but we wont be able to tell you.
My suggestion to you would be to not ask "why not" when we ask "why" or say not to do something. instead, come back with an idea of what you are trying to accomplish or explain what you are doing and trying to get as an end result. When we say dont do it, start asking if thats due to x causing y to break or another reason. take a little time to think about why we may be saying "no" or "dont" and wrap your head around it. We still may come back with short answers because you still have not done enough research. We dont like spoon feeding answers cause thats not how you learn or remember. We all went down these roads before.
you are working with a completely new platform over the cummins. ive played heavy in both cummins and dmax. Some stuff crosses right over, other stuff, not so much. The trans is something you will not be able to reference too. In stead, i suggest you start reading why we need defuel and get a grasp for it. then understand about how this is a clutch to clutch transmission and what that entails for shifting. then start going deeper and understand what are the toughest shifts to get right regardless of tuning and why. its these understandings that help you become a better tuner. That is assuming you want to "why".