Originally Posted by Adamantium
I think the loss on dd rollers is calculated not measured. Ie. it's the same for all GTRs as the variables used to calculate it are the same. I don't believe they measure coastdown on the individual car.
Correct. I was going by the fact that my car made 404hp at the wheels on a DD, and we now know that was pretty close to a genuine 485 at the flywheel (since seeing engine dyno printouts at the factory).
Using the standard DD calculation for a 4WD car, standard CBA GT-Rs tend to produce a claimed, calculated 506/510hp, but I now believe that to be erroneous (but irrelevant because you should only ever use a RR to show differences, not absolute power figures anyway).