enthusiast

+1 on what NJ-GT said about chassis dynamometers. A good tool to baseline changes but not to determine power of the engine at the flywheel.

Petevb

Nice curve. Since we're posting, he're my '06 997 cup motor on a Dynapack hub dyno.
No where near the torque down low (no variocam). Still, 380 rwhp/ 2150 wet (w/ roll cage)

spare tire

Think about it, No drive shaft running the length of the car to a large dif. If a light weight flywheel is worth 20lbs of rotating mass. Just another plus of the rear engine deign.

NJ-GT

Seriously, ignore the actual drivetrain loses.

The F430 has bigger loses on the drivetrain than the GT3, neither car uses a driveshaft. There are many factors in play here, hubs, bearings, axles, type of differential (try to rotate by hand an electronic e-diff and you get the idea), transmission friction and type, etc.

Power to the wheels is what matters, that's what moves the car, not the power to the crank.

Sharkwerks put a bone stock 2004 GT3 on the dyno, and it produced 378 rwhp, is it really a 0% drivetrain loss?

Just use the data from the same dyno on similar conditions and correction factors to compare cars, and use the dyno to verify the performance from engine upgrades (as long as you trust the operator).

Tuner1

Those are impressive power numbers. Actually a bit higher than I expected. How many miles on the car at the time of the dyno?

What I really want to see is 997.1 GT3 vs 997.2 GT3 vs 997.2 GT3 RS all on the same dyno on the same day

Will there be a larger power gap, from 2500-redline, between the two standard GT3s or between the two current generation 3.8L cars?