I think there is often a lot of confusion about the effects on the handling of making changes to your car's suspension.
I sometimes see things stated in these forums which are the opposite of the real facts of cause and effect in suspension set up, so I thought I would post this from my suspension bible ( by a guy called Greg Raven who raced Golf GTI's) to help to clarify things:

To reduce oversteer (increase understeer), try one of the following :

• Reduce weight transfer at rear by reducing rear roll stiffness
• Increase weight tranfer on front by increasing front roll stiffness
• Reduce aerodynamic downforce on the front tyres
• Increase aerodynamic downforce on the rear tyres
• Use wider rear tyres
• Use narrower front tyres
• Use heavier front springs
• Use lighter rear springs
• Use a heavier front antiroll bar
• Use a lighter rear antiroll bar
• Move some weight forward
• Use softer rear shocks
• Use harder front shocks
• Use more negative camber at the rear
• Use more positive camber at the front
• Lower the front tyre pressure
• Raise the rear tyre pressure
• Make the rear track wider
• Make the front track narrower

To reduce understeer (increase oversteer) you would obviously do the opposite of all the above.

Just about everything you do at one end of the car effects the way the car behaves at the other end.
If you think of a car as having 100% grip overhaul, that grip is then divided by the two ends.
If it has more grip at the front it oversteers.
If it has more grip at the rear it understeers.
What you are after is balance.
Inputs like acceleration, de-acceleration and braking steal from the amount of grip available, so the car can never have perfect balance in every situation, but what you are looking for is the balance that suit the car and your own style of driving.

The last bit is mine, I hope above is helpful