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      04-03-2013, 08:37 AM   #28
CanAutM3
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Drives: 2015 M4 DCT
Join Date: Jan 2012
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2015 BMW M4  [4.75]
2006 Audi S4  [0.00]
Quote:
Originally Posted by kotik View Post
just did another calculatro and it said 191mph (can't access any good calculators at work).

Anyone know the actual formula?

I believe this is the ratios:
6MT

1st: 4.055:1
2nd: 2.369:1
3rd: 1.582:1
4th: 1.192:1
5th: 1.000:1
6th: 0.872:1

Final Drive: 3.846:1
I also come up with 196mph (315km/h)

The formula:

Speed in km/h = RPM / Gear ratio / Final Drive * 60 * (Tire width * Aspect Ratio / 100 * 2 + Wheel Dia * 25.4) * 3.1416 / 1000000

RPM = 8400
Gear Ratio = 0.872
Final Drive = 3.846
Tire Width = 265
Aspect Ration = 35
Wheel Dia = 19

Last edited by CanAutM3; 04-03-2013 at 08:47 AM.