With a lot of help from Dzchey21, Tadd, and Haller, I was able to make a program that uses the VGT as an exhaust brake. It definitely does help slow the truck down and IMO it sounds good, but it's not too aggressive. It doesn't slow you down as much as some other trucks I have rode in, but IMO, it is better than nothing. Right now, I haven't figured out a way to make it engage at only one power level, but I am still working on it. Right now, it engages every time you completely let off the gas.
I will try to get screen shots and videos, but for anyone looking to try it right now, all you need to do is go to all of the "Desired Exhaust Backpressure" tables (there are 12 of them) and change all of the numbers on the X-axis on the "0" Torque line to "50". You can raise that number so it works harder, but that number does what I want it to do. It will depend on your RPMs/speed, how steep the hill is, etc. but unloaded I usually only see in the mid-30s for EBPs. I did try only adjusting one table, "Desired Exhaust Backpressure Hot Engine 1", but it never did kick in with only table modified.
I drive a stick so I can't help anyone on deciding how to lock the TC/Transmission tuning.
I will try to get screen shots and videos, but for anyone looking to try it right now, all you need to do is go to all of the "Desired Exhaust Backpressure" tables (there are 12 of them) and change all of the numbers on the X-axis on the "0" Torque line to "50". You can raise that number so it works harder, but that number does what I want it to do. It will depend on your RPMs/speed, how steep the hill is, etc. but unloaded I usually only see in the mid-30s for EBPs. I did try only adjusting one table, "Desired Exhaust Backpressure Hot Engine 1", but it never did kick in with only table modified.
I drive a stick so I can't help anyone on deciding how to lock the TC/Transmission tuning.