I'm a little confused.
I know the car hits max torque at 1400 rpm, but isn't that a function of engine load? So if you're cruising around at 20 mph in 3rd gear (assumption) and you stomp on the gas, the AT will downshift and the turbos will build boost. But if you were in already in a lower gear, the engine would have been loaded differently and therefore you would experience less delay. Is this correct?