With 640 horsepower courtesy of the Corvette Z06’s supercharged 6.2-liter V8, the 2016 Cadillac CTS-V is already one of the world’s most powerful production sedans. That includes removing the stock supercharger and replacing it with two turbochargers. Along with other modifications to the engine internals, Hennessey hints this setup will be good for an even 1,000 hp.