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Old 06-17-2012, 07:41 AM
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dunderhi dunderhi is offline
Next: '18 AMG GT Roadster
Location: MD
Join Date: Dec 2006
Posts: 6,866
Mein Auto: 15 M6 vert, 15 328dxt
Originally Posted by jjsC6 View Post
Everyone is talking about 60' times and ET being off. But the thing that would be bothering me is the trap speed. Trap speed does not vary much with the launch, and is a good indicator of the HP being put down. A bone stock 550 should be 108 mph. He is only picking up 2mph or so with 100 more horsepower. 500 hp in that car should be running more like 113 unless it is really hot out and/or high elevation.

It seems to me that the 500 HP M5 (the outgoing model) has run as high as 118 trap speed if memory serves, and 115 plus easily. I realize that car was a little lighter, thats why I'm giving this the benefit of the doubt and saying he should be 113. Maybe even a bit higher.
Using a calculator at Wallace Racing I get the following:
1) M5, 114.6mph and 4137lbs yields 512hp. (data from MotorTrend)
2) 550, 106.9mph and 4354lbs yields 437hp. (data from MotorTrend)
3) RajG, 110.6mph and 4550lbs yields 506hp. (from RajG's data above)
4) Me, 112.9mph and 4760lbs yields 563hp. (my best trap speed & measured weight)

I suspect BMW's stock numbers are in general underestimated, but I believe BMW quotes minimum performance numbers since manufacturing variances will produce engines with different power levels; every engine does not leave the factory with the exact same horsepower.

2015 M6 Drophead Coupé
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