Hennessey said it was a natural decision to turn to the Navigator because it has mostly the same 3.5-liter twin-turbo V6 engine as the F-150 Raptor, which it converted last year to the 602-hp 6×6 VelociRaptor. So it added engine management computer software upgrades, a stainless steel exhaust system, high-flow air induction and large front-mounted intercooler with blow-off valve. Dyno results in the video show the Navigator topping out at around 500 hp and 500 pound-feet of torque at around 3,800 rpm at the wheels; Hennessey says the 600 hp comes at 6000 rpm.
The upgrades are good to take the nearly three-ton SUV from 0-60 mph in 4.8 seconds, about 0.7 seconds quicker than the standard Navigator, and run the quarter mile in 12.9 seconds at 107 mph.
The tuning package will set you back $19,950, including installation. Additional options include 22-inch forged monoblock wheels, lowered suspension and Brembo brakes with six-piston calipers and 15.1-inch brake rotors. There are also HPE600 badges on the front door jambs and tailgate, and embroidered headrests. It comes with a three-year, 36,000-mile warranty.