[fpitas]

Originally Posted by KLM

Just read through the whole thread (again) and would like some input my experience.

During my last two track days I have encountered multiple forms of over and understeer which were readily explainable. What has been more difficult to understand and rectify is best described previously by the "pendulum effect" of the Elise in this thread.

On two different days in two different corners of the same track I experienced enough oversteer to warrant (what I thought) a sizable correction. In other situations I have learned a quick, but early correction settled the car. Those saves/catches were generally in slower, tighter turns. In the faster turns, my correction was too large and too late or so it would seem. The response to my attempt to save was tail out in the opposite direction (and another); a car version of a motorcycle tankslapper. What surprised me was during the movements from left to right, while getting progressively smaller angles, there was very little if any "on center" feel. It felt like trying to balance on a knife egde; even the smallest movement had the rear step out. In both situations, the result was a spin. If/When this occurs again, any suggestions? It is clear my gas, brake and steering inputs were incorrect. Should it be "two feet in" if I do not straighten it out after the first correction? That seems like the easy way out and I would like to learn through this experience. Thanks guys.

PS - shims are still in - this is a base car with RAC wheels - contributing factors?
PSS - age of tires were not the determining factor (first event was on new A048 - slide started with lift throttle oversteer / second event six months later on worn A048s exiting uphill, off camber - right rear spinning hard - the fun began when it caught).

My take on this phenomenon, FWIW, is that it is a mid-engined car, and will always be a bit tricky because of the rearward weight distribution, but the stability can be improved significantly by using relatively more front spring rate vs. rear spring rate and adding a (light) rear sway bar to eliminate the resulting understeer. I plan on trying this with my Elise, although I am having a little difficulty figuring out an easy place to locate a rear bar that won't need a bunch of bends.