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      05-03-2011, 01:24 AM   #10
swamp2
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Drives: E92 M3
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Quote:
Originally Posted by e1000 View Post
Hmm. The problem with statement #1 is that unless we change the gearbox, acceleration at a defined speed will stay the same, since peak acceleration will always be done in the lowest gear possible.
That is not a problem with the statement. A limitation perhaps but fairly minor. Just abstract one level further and realize that we are talking about ANY speed. You can also imagine the rule being applied to two cars both beginning at the same speed - a basic rolling drag race. The one with that can develop the most power (well best power to weight actually) will initially out accelerate the other. Once the speeds become appreciably different you can't use the exact same rule/formula. For this you need a full dynamic time domain simulation.

Quote:
Originally Posted by e1000 View Post
I would say your analysis of statement #1 is correct, however I'd like to add to the statement that it is conditional on how much traction is available. You are also correct that friction plays a role, but as speeds increase, drag becomes exponentially greater, and therefore a real factor as speeds climb.
Absolutely, should have stated the first assumption on traction. Sort of felt it was obvious/implied but it wasn't. Also as far as friction you mean losses right? I am talking about dissipation in the tire itself from its cyclic deformation. Some of that mechanism is certainly frictional but we are not talking about tire on road friction.
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