Theoretical Top Speed for C63
Using a GTR because I have one and MT has data on the car, I extrapolated the required crank HP required for me to achieve a particular top speed in my C63.
AERO HP drag = Cd * FA * V^3 / 150,000
Admittedly here are the flaws...
The frontal area and Cd are known for the GTR. For the C63 I obtained a twice printed C63 Cd and estimated the Frontal Area using a telephoto lens took a picture of my C63 in comparison to a picture of my GTR. The results are not particularly sensitive to FA, so the results shouldn't be way off.
The driveline losses are estimated. I used 15% for the RWD C63 and 17.5% for the AWD GTR. Most HP numbers are my own car / MT tests.
Biggest weakness is that I estimated the Other Losses to plug for the GTR crank HP and then used that number for the C63 to get crank HP.
However, if my math is right I'm not far off IMHO.
DISCLAIMER...
I own and love both cars, make no representations regarding stability at any such speeds. Additionally, I endorse a "take to the track you idiot" mentality.
Regards and let the flames begin,
Ron
Very interesting data indeed. I wonder if the drivetrain loss you're using for both the C63 and the GT-R might be a bit off. I recall most of us here are accepting 17% or even 18% as the drivetrain loss for the C63, and I would suspect the drivetrain loss on an AWD car like the GT-R might be even upwards of 20%, although I could be wrong about that.
In any case, an excellent topic for discussion.
Article here -> http://www.motortrend.com/features/p...t/results.html
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Did this too with my ML and My E50 before I sold it.







who took the pic?

