[arpad_m]

Originally Posted by JaxChris

Anything with the T87 or T87A TCM have this low-speed turn-in jerking. It would've been nice if with the T87A that GM would've added a different measurement for Performance Mode which would've used slowest wheel speed and then all other modes relied on average wheel speed (like the speedometer does). Sadly, I don't think the memory space was provisioned for dual mode source values. None of the settings I've seen HPtuners unlock for the Camaro show the transmission parameter source values. Could be that requested values are hard-coded and there is no way for us to tell the TCM to ask for something different.

JaxChris, thank you for the detailed explanation, it's absolutely enlightening and makes total sense. On the same note, are you sure this hasn't changed or been adjusted during MY 2018?

The reason I'm asking is that I observed this exact behavior to the dot with an 8L45 every single time when making a sharp right or left turn into my inclined driveway, but my current 8L90 has been somewhat surprisingly "bump-free" from day one, on the same roads and the same driveway doing the same maneuvers. I don't have to give it any special treatment, it just shifts properly and the car never jerks or bumps, regardless of the speed of approach,deceleration rate or turn angle/radius (I did perform a few experiments to make sure).