The Chevrolet Corvette ZR1 is the fastest and most powerful Corvette ever created. It has 755 horsepower and 715 pound-feet of torque on tap, and when used to its potential, it’s capable of sprinting from 0 to 60 mph in a staggering 2.6 seconds. These numbers are more than enough to leave people breathless, but one tuning company isn’t impressed. Not one bit, actually. Welcome, then, to the world of Hennessey, where 755-horsepower cars are shrugged off in favor of tuned versions of the same car, dialed up to as much as 1,200 horsepower.