some of the later North American cars sit higher than the factory intended simply to meet US bumper height regulations, and springs do weaken with age, getting new factory springs (what the makers intended before the DOT compromise) to correct these problems is reasonably risk free if you are staying with stock tire sizes. But Spyros is right, there are so many factors to be considered, Tire width, tire diameter, shocks, etc. the commonly held opinion is that lowering the car is an improvement, just like replacing the Spica with webers. the road and a race track are 2 different enviroments. If you do a lot of research on this you might be surprised at some of the options you have when it comes to increasing your Handling "performance" and still maintaining reasonable ride quality.