Sat Mar 21, 2015 4:33 am by Packbat
From what I can understand - and bear in mind that I don't know what I'm talking about - the ideal weight distribution would put approximately the same weight on all four wheels, with a little bit (~1-10%) extra on either the rear wheels (in a rear- or all-wheel-drive car) or the front wheels (in a front-wheel-drive car). The idea is to make each of the wheels take as large a share of the total work that needs to be done moving the car around the track as it can, so that you get as much grip as possible out of the entire system.
That said, the biggest effect weight distribution has is how you tune your suspension. If you have more weight in the front, you need more spring and damper in the front to deal with that.