Well most stance guys have really high preload so they don't rub in the fenders as much as with out preload. people use preload to get the right stiffness out of their coilovers. there is a happy Medium of preload to help u handle better. Most of the time for track use its not goods to have a lot of preload cause u will be bouncing everywhere and not handle very well at all.
yeah I kinda assumed all that I was wondering if any harder than that "happy medium" (which is usually pretty small amount, for example my recommended preload is 4mm. and the car starts getting quite bouncy as you push more than 15mm preload) is bad for the shock/springs after awhile?