Guys, try this link. It has the chart for checking Ackermann. The bottom line is that if your car is not "balanced" and the outside front tire is doing most of the work in a turn, then Ackermann may help turn entry and will have little adverse affect mid-turn. If, on the other hand, you have a more modern set-up (mostly a function of moment centers and roll stiffness) where both front tires are contributing to the turn, then Ackermann will introduce mid-turn drag that will hurt performance.
Pappy
http://www.circletrack.com/chassiste..._steering.html