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      10-06-2012, 09:15 AM   #191
CanAutM3
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Quote:
Originally Posted by swamp2 View Post
Polar moment and weight distribution are different measures but are closely related. Low polar moment is achieved easily in a mid engine. Mid engine also contributes to equal weight front and rear. A large polar moment comes from a large amount (%) of weight (again an engine is a key contributor) far away from the center of mass. Polar moment however also depends on the total weight itself. A scale model version that is exact will have a correspondingly scaled polar moment, however, its weight distribution will remain unchanged.
Read my post again, I am referring to axle weight distribution, in response to the post I was replying to. Not overall weight distribution.

Using the centre of gravity as the referential, polar moment and axle weight distribution are not related. Polar moment depends on how weight is distributed around the centre of gravity (how much and how far). Axle weight distribution depends on the position of the centre of gravity relative to the axles.

Now under dynamic conditions, it gets more complicated, as a car does not necessarily rotate around the centre of gravity.

I don't want to get too technical here, but for those interested, there is a very good book published by the Society of Automotive Engineers called Fundamentals of Vehicle Dynamics by T. D. Gillespie that explain these principles very well (with plenty of equations ).

Last edited by CanAutM3; 10-06-2012 at 10:35 AM..
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