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Originally Posted by blue2000s
I'm running out of ways to explain this folks. Acceleration comes from force, which is directly related to the torque at the wheels and the wheel radius. I'm trying to make it as understandable as possible. Like I said above, you CAN use power, but that's not the way it's traditionally done.
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blue, this is not true. force means nothing without MOTION. force that causes motion is WORK. work performed quickly is POWER.
Example: you have 2 identical cars w/ different torque curves. both cars are currently making 300 ft-lb of torque.
Car A: Torque = 300 ft-lb, RPM = 8000, HP = 457
Car B: Torque = 300 ft-lb, RPM = 4000, HP = 228
now, as you stated earlier, because these cars are making equal torque, they are accelerating at equal rates. BUT, assuming 1:1 final drive: car A is doing this from 91 mph while car B is doing this from 45 mph. even though they are gaining speed at the same rates, car A is travelling MUCH faster because it is performing WORK at twice the rate (double the POWER).
it is a common misconception that shifting just above peak torque will yield fastest acceleration times. gearing allows us to take advantage of power, though, and the object is to do the WORK (i.e. move 3000 lb of car 1/4 mile) as quickly as possible. work / time = power.