Refining Shifts-LBZ

[killerbee]

I have no plans to get into the TCM, so with that in mind:

can shift defueling (for ride refinement) be refined/adjusted in the ECM? Share your opinions/techniques. Here is an example. This shift is slightly over-defueled, 31 to 22 mm. What would you do to increase this to say, 25?

It appears that B1102 is not the answer?

[bballer182]

I'm going to drop Nick from duramaxtuner.com's name in here knowing that he lurks this forum on occasion and will find this thread and will probably shed some light on this topic. This to has puzzled me and i have not dug into it, as i have wanted to for quite a while.

[LBZoom]

I dunno if there's a way to do it in the ECM but there is a de-fuel adjustment in the TCM that adjusts based on percentage...but is there an easy way to log de-fuel percentage as it relates to the specific table in the TCM?

[bballer182]

It's actually a combo between the ECM and TCM. and the % that you are talking about is only for 8.1 gas engines with the allison.

[LBZoom]

okay, so is it still somewhat of a mystery how it can be changed then? I'd like to maybe have a little less de-fuel during my part throttle shifts but I've not really known how to go about it really...

[JoshH]

It appears that B1102 is not the answer?

Why?

[killerbee]

I am still playing with it, and there is some 1102 impact. 1102 impacts more than just shift fuel, so it seems to be a tricky business.

[JoshH]

I've said it a bunch of times before and nobody listened to me, but there is no way to adjust the amount of "defuel" on an LBZ. What I mean is, I have not found any table that controls how the engine torque reference numbers react during a shift. The only way I have found to change the defuel is by playing with B1102. Like you said though, it's tricky because there is so much that relies on that table.

[killerbee]

...main fueling is one of them. So if you increase an 1102 entry, it seems you are just scaling both fueling and "defueling" equally.

Yes, no?

Honestly, this has been a burden, and not just for shifting. My biggest issue so far, is that there has not been a way to reliably log the torque values that these tables portray, and that the cal_link is not sufficient to carry through from one table to the next. It's like trying to do complex differential calculus, while drunk. The only cure is to go to sleep.

This is not a complaint on the software, I understand it is a work in progress for the bosch ecm, I just think this one area (torque continuity), if fixed, will make a lot of other things easier.