Max torque range?

[technical]

I just got a 2500HD 6.0 with a 4L80E 4WD. I decided to throw a tune into this one since I'm buying.

One of the first things I wanted to do is raise the max torque settings. This would not only be the first 4WD tune for me, but the first A4 tune as well. I'm a bit confused with the torque values for B6615-B6620. The current settings for max rear axle torque, for example, is ~13,500 Nm. Fine. Why on earth then is the max setting ~58million Nm? I want to raise these values to something reasonable vs. disabling the torque limiting all together. I'm just having a hard time believing even half of 58million Nm is reasonable...so how on earth do these numbers translate to the real world?

FWIW I've raised these values considerably and noticed that bog from a standstill is somewhat better, but I'd like to have some reference point to work from since it seems either the max value is garbage or the factory put some serious torque management into this vehicle. Any clarification would help.

--thanks.

[Ira]

Depending on the processor they used and the incremental value they used it might be like that. I would start by ignoring the max value and trying reasonable values and scanning after each change while watching the timing and fuel to see if you're getting hit by torque management. It might end up that the gears and converter you have are going to make you feel bog no matter what you do.

Ira

[technical]

I'll have to play with it I guess. It'll take longer to find a suitable set of values, but I know this truck can light up the rears without the TM entirely. I raised the values to ~1 million and it feels much different now but I'm not looking to race with this truck. I just want to remove most of the TM without causing traction issues especially when it's raining.

Also this truck has 4.11's and what seems like a much looser converter than my 5.3 Avalanche. I'll try going halfway (~25million) and work from there.

--thanks.

[GMPX]

It does seem totally crazy, but the reason is the actual calculation allows it to calculate out that far, I suspect the simple reason is by handling the values as 32bit numbers it made it easy elsewhere in the code to manipulate some data.

Cheers,
Ross

[technical]

That's what I was thinking. I figured the max value probably doesn't mean much in the real world. I was just hoping to find a decent reference point to begin tweaking vs. iterating 1 million times backwards from 58 million. :lol:

[ToplessTexan]

I was just hoping to find a decent reference point to begin tweaking vs. iterating 1 million times backwards from 58 million. :lol:

Binary search is your friend. Take a step halfway in one direction (say 29M). If it's better take another step halfway (say 14.5M), if it's worse take a step halfway in the other direction (say 43.5M). Lather, rinse, and repeat. This can be a very quick way to find a decent starting point.

[technical]

One step ahead of you.

FWIW half of the max value ain't too bad. A quick goose of the throttle barks the tires even with the AC on.