Hey smorg, great work! It appears Model S is engineered to have max torque up to 60mph. WRT differences between Perf and non-Perf, we know that the non-Perf PEM, cabling, and Motor are good to deliver up to 900A to the motor whereas the perf upgrades that to 1200A. I base my calculations on that and the assumption that there are no changes other than electrical dimensioning. That would mean 33% more torque, raising 415Nm to 553Nm (that is 305ft lb -> 407 ft lb). The flat torque curve reaches peak power at 5250rpm or 75kph/45mph. Between 45 and 60mph, the torque curve begins to drop but is still above non-Perf. Finally, above 60mph both cars should have similar acceleration. I found the wikipedia entry on torque most helpful. 415Nm at 7000rpm gives 305kW.