Note: these specifications came from various websites and the actual figures may vary.
427 Cobra (street version)
425 hp / 2150 lbs = horsepower per pound ratio of 0.197
Honda VF750 (stock)
90 hp / 500 lbs = horsepower per pound ratio of 0.180
Viper Roadster
510 hp / 3410 lbs = horsepower per pound ratio of 0.149
ProjectVF
80 hp* / 620 lbs** = horsepower per pound ratio of 0.145
Porsche 911 Carrera
355 hp / 3131 lbs = horsepower per pound ratio of 0.113
Suzuki Burgman 650
50 hp / 524 lbs = horsepower per pound ratio of 0.095
Cadillac STS V6
255 lbs / 3921 lbs = horsepower per pound ratio of 0.065
*VF750 engine de-rated 10 hp for used condition and operating one mile above sea level
**Stock VF750 = 500lbs - 30lbs (old bodywork) +150 lbs (new bodywork) = 620 lbs (est)