As a reference, there are many documented stock Z06's making about 454rwhp (some more, some less). At 505 crank, that gives us 11.25% drive train loss. If we apply the same 11.25% to the Nissan, that gives us about 484 at the crank. Now even for a RWD car 11.25 sounds extremely low, for an AWD car, probably not. So either the Z06 and GTR are making more power than rated, or the percentages we are using to calculate crank HP are completely incorrect. Somthing just doesn't sound right. We know the loss factor is definately higher in a 4WD, but how much is not quite sure. To say it's double is probably not right.

But here is the real quandry...GM for a few years has been using a new third party testing procedure that is becoming the industry standard, along with European manufacturers. I have always heard the opposite of Japanese manufacturers and their testing procedures, that their tests consistently reflected higher than real world figures, which in the past year or so has changed, as they have adopted the same third party testing procedure as GM. There were articles where many Japanese cars had actually reduced HP ratings recently due to the new testing procedure without any mechanical changes.

So as an example if the Z06 motor is rated at 505hp and owners get about 454rwhp as a median, and the tests are being performed under new strict 3rd party procedures, what is going on? Even 435RWHP for the Nissan with a conservative 16% drive train loss, still puts the car at around 505hp.

So are all the motors underrated, or is our calculation method way off base?

Does anyone have a dyno of a 911TT (non-mustang dyno)? I would lke to look at all three and come to some kind of rough conclusion.