The NSX needs an engine like this one.

[StockTeg]

http://www.supercars.net/cars/2003@$TVR@$T440Rg.html

4.2 liter Inline 6
440 hp@ 7600 rpm and 350 ft lbs@ 6000 rpm.
It also redlines at 8000 rpm.

I know Honda can do something better than a 3.5 liter for the next NSX(HSC).