The NC PRHT would be expensive to buy, but anyways, it'd weigh about 2650 at the end, which, for 400 WHP, gets 6.6 lbs/HP. That's acceptable. 300 WHP would be 8.8 lbs/HP, which is getting too high.
I know, high is relative, but I'd want this thing to be able to crush Corvettes, Mustangs, Bimmers, and Rexes.