Duramax Tahoe. Tuning the allison 5 speed

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,320
352
83
Central OH
Sounds like you want it to drive like a gasser, and with the TCC applied "around town" that's not going to happen without a little lag IMO.

I tried it with my truck, having TCC applied in 2nd during regular shift schedule then bumping shift mph up until I felt it was on the verge of being too noisy for in town driving (like idiots who cruise with the T/H on). You can't expect the trans to unlock the TC and downshift (or stay locked in and downshift twice) all the while fueling hard enough to build boost to pass someone in a timely manner.

I think a good converter would help a lot
 

gearguts

New member
Jul 30, 2016
18
0
1
I actually got it narrowed down pretty good now. No lock up until fifth and about 90 kph at about 35mm3 IIRC, then once in I like it to hold until about 74 so I get a decent range between lock and unlock. A little different than what most people seem to like but It sure works nice for me. I set first to fifth to come in a bit earlier, around 1500-1600 rpm and it keeps it quiet. I hear ya about the " to noisy for in town driving" I find shifting over 2000 is pretty noisy. Don't get me wrong though, I do love the noise ! Just not all the time..