its not turbocharged
its naturaly aspirated
its not the hayabusa I-4 … its aa V8 derived from the busa engine
and theres a world of difference between a cars top speed and a motorcycles top speed, cars have a whole lot more lost HP (wider tires, more tires, more bearings in the suspension, larger brake rotors, heavier wheels, much heavier transmission internals) add in alot more wind resistance, and more rolling restance from the tires, and you loose ALOT of top end compared to a motorcycle
160 is still a damn nice number (and in an open car, it would probably scare the shit out of ALOT of people) … ive seen 150mph+ … its definantly a mind fuck to watch mile markers go bye looking like tracer rounds out of a machine gun