Ok, this is simple. You use more than one gear in the 1/4 or whatever. Where is the motor reving in each gear? Who cares if you have 800 lb-ft. at 3800 rpm; you're not driving the car at that rpm after shifting out of first. Then factor the available amount of engine torque to that particular gear ratio (hint, second has 1.93/3.21 the torque of first gear). Again compare to the Z06 mph and gears. Now add more weight for the TT vs. the Z06 . . . voila!