I can tell you that even a small change in polar moment of inertia can make a noticeable difference in a 1/12th scale. Not in all corners, but VERY noticeable in some. I did some experimenting with a 4 cell T bar car a few years back. It had a couple different ways of mounting the cells. One holder had them out a bit further, one more in, same fore/aft weight distribution either way. The results:
Most of the track, the car felt exactly the same. But right in front of the drivers stand was a fast right, left, right chicane. Batteries out, the first right was wide open but the quick flip of the wheel to the left would induce double steer and force me to back off. Batteries in, it was full punch, on the line and perfectly stable. And again, this was a very small change in mass distribution. Lower moment of inertia will give faster direction changes and be more stable when making those changes.
Last edited by wingracer; 07-29-2011 at 06:11 PM.