a lot of the time its just how your driving the car... entering corners too hot can many times result in understeer...

Also when the car starts to understeer, natural instinct tells you to turn the car further into the corner, but this is exactly what to NOT do.. when the car begins to understeer, you have a few options.

A: turn the wheel slowly back to neutral, at times the car will begin to grip and turn in sharper (seems backwards but it works!)
B: ease up on the braking if you are heavilly breaking (try to get the tires back inside the "traction circle" this is the same tatic as A: but just from another side of the circle)

C: do something violent such as a clutch kick, drag, or e-brake (these are fine for drifting, but for track racing arent the best idea speed wise)


So there are others, but really try your driving before you go modifying the car, even the worst noseheavy FF cars can be oversteered if unbalanced entering the corner.. and the most oversteering cars can plow through a corner if the entry is too fast and the driver inputs too much braking and wheel turn at once (outside tire's traction circle).