What makes this personality transformation even more impressive is how few changes were required for this infusion of character. Really, other than a very modest bump in compression to 9.5:1, all that Jaguar did was uncork the exhaust and remove the engine ECU algorithm that limits torque output. It was made possible by the more robust torque converter added to the ZF automatic (transmissions, especially automatics, are almost always the weak link in the powertrain when it comes to the massive torque infusions that result from super or turbocharging). Current XKR owners will, of course, note that a whole bunch of performance is but a pipe and chip change away, though using it in the first few gears may destroy their transmissions.