OVERVIEWAn all-new LS9 motor produces 620 horsepower at 6500 rpm and 595 pound-feet of torque at 4000 rpm. Delivering 100 horsepower per liter, the supercharged 6.2-liter V8 is mated to a close-ratio six-speed manual gearbox with a new high-capacity clutch designed for the increased power. The twin-disc 260mm design provides plenty of clamping power, while maintaining a relatively easy clutch action.GM has not disclosed specific performance numbers, but the company admits a top speed of 200 mph is very likely. In terms of acceleration, the ZR1 most definitely beats its Z06 counterpart, thanks to a 115-horsepower output advantage. Since the Z06 rockets to 60 mph in just 3.6 seconds, it's a safe bet the ZR1 will be much closer to the 3.0 mark.