[Thirdgen89GTA]

If its 475whp then its not fast enough at 120mph. If a 350whp C5 Z06 can match its trap speed then somethings not right.

475hp is about right. Certainly I believe the engine could have been under rated. GM's done it with every V8 born in the corvette that found its way into the F-body. Factory freak LS1's have put down near 300rwhp when they only made 315hp at the crank. If you go with that then you get about 360hp. The LS1 in the Corvette was rated at 350hp, which would explain why the LS1 F-bodies put down some impressive numbers. Internally the heads/cam of the engine are identical between the Vette and F-body LS1's. Only differences remain are the filter/intake charge piping, and exhaust. LS1 Vettes didn't put down such impressive numbers, they put down numbers that were right in the ballpark using expected drivetrain losses.

IF thats true then its sad, because the C6 Z06's make 505hp and trap near 127mph (ranger's and his C6 Z06 come to mind) with about 460whp. Yes the GT-R is AWD, so its parasitic losses are greater.