Sway Bars
One of the parts that can have the most dramatic effect on a cars handling charectaristics and reaction to steering input is a sway bar. However, this part of the suspension is often overlooked when a driver seeks to improve the handling characteristics of their car.
A sway bar is a length of solid or hollow steel tubing that connects the right and left sides of the suspension together. Its purpose is to provide an increase in cornering stability by reducing body roll and maintaining proper suspension geometry throughout the radius of a turn. It does this by using the sub-frame of the car as a pivot between the right and left endpoints of the front or rear suspension. As pressure is applied to the suspension on one side of the car, an equal amount of energy is transferred via the pivot, to the opposite side of the car. The result is that both sides of the car remain relatively even through the turn. This allows both wheels to maintain proper camber and caster angles throughout the turn as well as use all of the tires contact patch to react to the drivers inputs. Because this has the effect of reducing body roll it is often referred to as an anti-roll bar.