[Tom C]

Or then again not...

Please go to this thread.
http://www.m5board.com/vbulletin/f10-m5-discussion/197987-stock-f10-m5-dyno.html

Not quite the 620-650 bhp you suggested.
http://www.m5board.com/vbulletin/f1...scussion/197432-sport-auto-reports-12-9s-f10-vs-15-6s-e60-hockenheimring-2.html

Those type of dynos where they come up with the crank horsepower are just not accurate. Their calculation is based on a "coast down method"...where they run the dyno as usual....and then once the run is done to redline...they throw the car in neutral and measure how fast the car's wheels coasts down to a stop on the rollers. What they don't tell you is that there are "estimates" in the way the computer calculates the so called "crank horsepower" figures. There are just too many variables for it to accurately measure the crank horsepower properly. It is about as accurate as me saying all rear drive manual transmission cars have 15% parasitic loss when measuring hp on a Dynojet dyno....

Tom

 

[Tom C]

I get the AWD advantage. So how come the RS-6 is so slow?

The RS6 is extremely heavy (the sedan weighs around 4,350lbs) and is mated to a true automatic....which has more parasitic loss than the dual clutch transmissions in the F10 M5 and GT-R.

Just an FYI, I think the GT-R's parasitic loss through the drivetrain is closer to that of a RWD, manual car given its stock one piece carbon fiber driveshaft that goes back to rear differential/transmission. Also, the torque split is 50/50 between the front and rear wheels at low speed...as speed increases... it becomes more of a RWD car...and will push power to the front wheels as needed...not to exceed 30%.

Tom