Source: Lotus West
Date: 1978
LW# 00MC095

I suspect there a lot of Lotus drivers out there who've seen cars compared on the basis of lateral acceleration ("g's" of cornering force) and wondered how to find the value 'of this mysterious quantity for their own car. The method of doing this is really quite easy. First, find a suitably large parking lot, etc., that you can use for a skid pad. Lay out a circle, using chalk, etc., of known radius (most any radius is OK - about 50 ft. seems to be a good size). Next, have your girlfriend, wife, etc. (both?) time your laps as you drive your car around the circle as fast as it is capable and still remain on the circle. Record the time of your fastest lap and the radius of the circle. (Incidentally, your car's steady-state handling characteristics can be determined at this same time. As you reached the limit to how fast you could drive around the circle, did the rear end of the car start to slide out first, trying to swap ends with the front? If so, your car oversteers. If the front end of the car felt like it was plowing off the circle first, your car understeers.) Your car's lateral acceleration in g's is given by the following formula:

Ken Dodge
Culver City, CA