The Hennessey Venom GT hit 270.49 mph at NASA’s old Space Shuttle runway in February 2014, a speed that should have made it the fastest production car ever built. It isn’t official: Guinness requires at least 30 units, and the small Texas shop built far fewer, on top of running in only one direction. Read on for how a 1,244-horsepower twin-turbo LSX, a 2,743-pound Lotus-based chassis, and a Ford GT gearbox produced America’s fastest car, official or not.