When a Mustang is lowered, the front roll center changes due to the new position of the suspension pivot points. Lower the car too much and the front roll center drops to well below ground level, and worse than that, the roll center moves side to side as the body rolls, resulting in lost grip and erratic handling. The lower roll center causes the body to roll more easily. Countering this tendency usually requires a significant increase in front spring rate to simply control the added roll due to the lowered the roll center. This higher spring rate not only hurts ride quality, but it also reduces grip on rough surfaces, as the stiffer springs cause the tire to skip over bumps instead of following the contours of the road. The X2 Ball Joint
was designed to eliminate these problems by correcting the front roll center geometry. These balljoints have a longer shaft, to raise the spindle relative to the balljoint pivot point. Spacers for the springs are included in the X2 kit to maintain the same ride height as a stock balljoint, but with a much improved roll center height. With the roll center restored to the proper height, smaller front swaybars and softer springs can be used. The result is a suspension that works for you to accommodate the small and large imperfections that are in any road or track, allowing the tires to stay planted on the ground where they belong.