Originally Posted by Solracer
I have always understood that when you change a sway bar you are increasing or decreasing traction on the opposite end if the car, just like when you up your spring rate, because essitially a sway is just another spring.
this hold true for the older cars which did had much more twist in the chassis.
in the new cars it's a bit different.
for example in my M coupe, a thicker anti-roll bar actually helps with exit speed. It allows you to get back on the throttle much sooner.
But you are right that anti-roll bar does change the spring rate, but only when one side is loaded. So if you hit a bump with with wheels (front) then the effect of the anti-roll bar is negated. If you hit the bump with one of the wheel, then the impact will be much greater.
Also sway bar is better than a spring because the stiffness can be adjusted easily.