Leave it to John Hennessey to make a great car even better. He does that from time to time. After already announcing the specs for his upcoming supercharging kits, Hennessey himself gets behind the wheel of a stock Mustang GT to offer his insights. He's only put about 100 miles on the car, but so far he's impressed. More importantly, he immediately sees room for improvement in both performance and sound.

Compared to the just unveiled GT350 Shelby (500 hp and 411 lb-ft), Hennessey's top-of-the-line upgrade kit, the HPE700, will bring total output to 717 hp and 632 lb-ft of torque. Yes, that's Dodge Challenger SRT Hellcat territory. In the meantime, check out Hennessey taking that stock Mustang GT up to 150 mph.