With people reporting that the Allison shifts better with non-defuled shifts(or seems to), I'm curious: How do you do it? I was told that the defuel comes from the base torque and torque based fuel tables (A1210 & A1109 respectively for DSP1, B1103-B1105 & B0742-B0744 for the main tables, I assume). I set A1109 to 110mm3, and discoverd that that's actually the amount of fuel the ECM is going to command to be dumped in (my fuel rates went way up for about 1/4 second). Obviously, I mis-understood something. What table(s) woult I need to change and how to kill defuel?

Thanks

I dont really seem to have a problem with defuel on my truck. not nearly as bad as my bro's LBZ anyways. I'm not sure if I have the issue or not but as far as I'm concerned my truck doesnt really defuel during shifts. It just bangs another gear and chirps the tires sometimes.

I didnt adjust anything for defuel I dont beleive. I'd have to look more closely at what I changed there again. Let me know if you want me to email you my tune and you can look at it. I'm going to guess by your 1/4 time that my tune is fairly close to yours performance wise.

Dave,

What you'll have to do is set the tables so that when the shift is commanded, the ecm will command the same amount of fuel that was being commanded before the shift. So instead of setting the table to 110, set it to whichever mm3 you were at before the shift per the log.

It's not like a gasser where you can just set the torque reduction to zero and be done with it.

Make sense?

Nick

Thanks Nick, That's the direction I though I had to go after setting the whole table to 110 and watching the fueling spike instead of stay the same or drop. So I guess it's log-city for me.

I think I am experiencing the same problem... All of my drag logs show a massive spike in rail pressure on all the shifts... I guess that means that since it is commanding so much less fuel, the rail doesn't have time to regulate the pressure... I hate to ask this (feel like I should be paying for this type of information), but what table am I looking at to know what was commanded at the shift point?

B0742-B0744 (non DSP) are the tables that command how much fuel is injected during the shift. Sounds like you are experiencing something different. The spike I was getting when I made my change is it dumped 110mm3 of fuel in at the shift becasue that's what I set the table to, instead of the dip you get when it defuels. A spike in rail pressure is something else.