A guy at our local car show brought out his Ford GT with a Heffner Performance 1000TT Twin-Turbo kit. Heffner removes the factory superchargers and replaces it with a sheetmetal intake being fed by two Garrett GT35R turbos. The GT made 933 hp on the Heffner chassis dyno.
Car and Driver tested the vehicle and came up with the following info:
Street drivability: 4 stars
Zero to 200 mph: 18.9 sec
ΒΌ-mile: 10.6 sec @ 152 mph
0 to 200 to 0 mph braking: 1089 feet
Total time, 0 to 200 to 0 mph: 26.5 sec
Of course, these mods don't come cheap.
Engine/Transmission: $42,950
Suspension: $6300
Brakes: $3000
Wheels/Tires: $6000
Body/Interior: $5000