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      05-03-2011, 09:27 PM   #20
e1000
that's what SHE said!
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Drives: 2011 E92 M3 ZCP
Join Date: Jun 2010
Location: OC

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Quote:
Originally Posted by swamp2 View Post
Think about it some more. When driving aggressively (i.e. for maximum OVERALL acceleration) in an M3 you are almost always above 5000 rpm. The peak INSTANTANEOUS acceleration in any gear is way down around 3000-3500 rpm! In most sporty engines you simply never "use" peak torque nor do you hit peak instantaneous acceleration. Odd but true.
The problem with this statement is that it is only true for 1st gear, and that's precisely why I added the part about acceleration being traction limited. If peak torque of the S65 truly comes at 3000rpm, it theoretically is the max instantaneous acceleration the M3 is possible of IF AND ONLY IF the tires don't break loose.... and we all know if traction control is off, they will most certainly be roasted to a pulp.

In all other gears, 3000rpm in that gear (for example 3rd) will be inferior to a higher rpm in a lower gear (2nd) simply due to the multiplication factor of the shorter gear (numerically higher) delivering a greater ammount of resultant torque to the wheels. The alternative is partial throttle acceleration, meaning the torque curve is artificially limited by the driver to match the thresholds of traction, thereby changing the point of peak power.

In the end, we are saying the same thing. I just want to make things clear so others don't get the wrong idea.

Lots of people get the relationship between HP, torque and gearing all wrong. Remember folks, torque is multiplied through the gearbox, horsepower is not.
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