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      10-05-2012, 10:55 PM   #181
swamp2
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Drives: E92 M3
Join Date: Sep 2006
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Quote:
Originally Posted by mhabs View Post
Would be interesting to do the torque multiplication math through the gears/diff/wheels to really see which car is producing more torque to the wheels.
Better yet how about actual drive force in N vs. speed? Drive force is even more fundamental than wheel torque and can be better compared apples to apples. That being said acceleration is loosely force/mass and these curves do not include the 1Ms mass advantage.

For the 1M have assumed a torque curve shaped like the one supplied by BMW but with a peak value so that 360 hp is the peak hp. The factory supplied curve is used for the M3. Both cars use a 12% drive train loss.

Prior conclusions I've supplied are consistent with this. The cars are close. M3 on left 1M on right.
  • 1st gear - About even. Slight advantage for the 1M in lower speeds (only if you can avoid wheelspin, which typically does not happen WOT...). At higher speeds the 1M dips down to about 13kN, however the M3 never goes below 15kN.
  • 2nd gear - advantage to M3 (especially since we are concerned with the part to the right of the intersection with 1st gear curve in blue)
  • All other gears clear advantage M3 (assuming WOT and shifts at redline of course)

You can see the effect of the high redline and very wide torque curve in the M3. The M3 curves just keep going and stay flat while the 1M curves all badly taper off. These curves do loosely mirror the torque curves in shape. You can really feel this too when driving - the M3 just goes linear like a turbine engine, whereas the harder you push the 1M the more it falls.

Note: Real world curves will obviously be smooth. This is an artifact of rpm "bins" rather than smooth power and torque curves.

Funny how good power to weight predicts things compared to crank torque.
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Last edited by swamp2; 10-05-2012 at 11:05 PM..
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