What is happening, is the torque control that is programmed into the ECU taking affect when the TCU tells the ECU that it is going to shift, or when you start from a stop. Changing the TCU will not help this. But, I think that someone posted a how to on dissabling this function when a manual trans is installed. Not sure if it will work for the auto trans, but it might be worth a try.
I dont think its a good idea though. The SVX puts down a lot of torque and with %100 traction, it will be very hard on the front diff, clutch packs, and torque converter. However, there is a trick to keep the TCU in power mode, and it makes the SVX a whole new car, especially with 4.44s
