I have about 120 miles on the truck and have got a chance to "feel" it out. I noticed that at light throttles leaving a stop that just after every shift the truck seems to "nose over" or what I call "tip in". It feels like the fuel is trimmed back and then once the shift is made it spools right up again. Is this "de-fueling"?

If so what happens from a performance stand point once power is added and the truck is pushed to a WOT trot?

Howard

It takes some RPM and a little "load" to make the turbo do it's thing. Turbos are driven by the rapid expansion of exhaust gasses leaving the cylinders. You say this feel is during "light throttle" shifting. At light throttle, when the RPM drops during the shift, there is no real expansion of hot exhaust gasses and the turbo backs down accordingly. At higher throttle settings, and higher RPMs, this feeling will be minimized. If you feel it during full throttle shifts, then it would be from defuling.
Bob

It takes some RPM and a little "load" to make the turbo do it's thing. Turbos are driven by the rapid expansion of exhaust gasses leaving the cylinders. You say this feel is during "light throttle" shifting. At light throttle, when the RPM drops during the shift, there is no real expansion of hot exhaust gasses and the turbo backs down accordingly. At higher throttle settings, and higher RPMs, this feeling will be minimized. If you feel it during full throttle shifts, then it would be from defuling.
Bob
Bob, I am very familiar with turbos....at least in a "gas engine" situation. I have a late model performance fuel injection shop and deal with high end turbo applications all the time. Many of them "one off" custom setups.

If your foot stays at the same throttle angle and the motor is building boost, there is no loss of expanding gas. I ended up NOT using a 6 speed tranny in my twin turbo 427 Nova project because the automatic would always keep the motor "on boost". The feeling is minimized at higher throttle angles and loads. Maybe what I am experiencing is the Allisons manorisms!!

What you are experiencing is defueling. It's done by the computers in the Allison and the Dmax. It's a controlled shift. Normal. When the Allison shifts the engine defuels to help the transition and smoothen things out.

I believe the Juice Attitude allows you to turn defueling off.

What you are experiencing is defueling. It's done by the computers in the Allison and the Dmax. It's a controlled shift. Normal. When the Allison shifts the engine defuels to help the transition and smoothen things out.

I believe the Juice Attitude allows you to turn defueling off.Hoot, thanks for that logical answer! I played with it last night and it definately feels that it's a controlled "shut down" for just a second. At high loads it is not present. It does however interrupt a linear power feel.