Steeda probably knows more about suspension systems than nearly any other aftermarket parts manufacturer for the Ford Mustang. They clearly know more than most of us, because on first glance at their Mustang ball joints for lowered Mustangs, I was scratching my head as to the possible difference this tiny piece of metal and bushing could possibly make on Ford's complex suspension system. The answer is extremely subtle, and based in the physics and mathematics underlying how the suspension transfers force, and how the Mustang's chassis handles load transfer through turns and hard corners.
One of the key factors in suspension performance is controlling load transfer, or the change in weight on each of the vehicle's four tires during acceleration, braking, and cornering. Lateral acceleration through cornering causes the car's sprung mass to roll toward the outside of the turn and places more weight on that side of the Mustang's suspension. The inherent weight transfer, and body roll, can be greatly reduced by a number of methods including sway bars, suspension roll center relocation, reduced sprung mass and lowering springs that lower the center of gravity height and increase suspension spring rates. Lowering springs lower the car's chassis, and with it the Mustang's center of gravity height in comparison to their OE counterparts. In turn, the reduced center of gravity height reduces the amount of load transferred to the outside wheels during a corner. Additionally, lowering springs typically posses spring rates that are higher than their OE counterpart for to prevent the suspension from bottoming out and/or crashing on poor roads and to reduce chassis roll when cornering.
However, installing lowering springs alone causes significant suspension roll center migration that can negatively effect handling. The suspension roll center is the geometric point where cornering forces placed on the chassis transfer onto the Mustang's suspension. It's not uncommon for lowering springs to lower the roll center height more than the amount they reduce the center of gravity height. This shift in roll center actually causes MORE body roll when cornering, especially if the lowering spring rates are not increased proportionally. That's where Steeda's broad line of X-series ball joints come in. Each ball joint is specifically designed to repair the roll center location and dramatically reduce body roll. These ball joints have a longer stud than their OE counterparts that effectively relocates the lower control arm closer to horizontal, and in turn, helps restore the factory roll center location. Steeda also strongly recommends the installation of one of their excellent bumpsteer kits to re-align the tie rods with the lower control arms. Each ball joint kit requires at least an 18 inch wheel for proper clearance and installation.
All of these innate requirements generally turn away most customers from Steeda's ball joints. After all, lowering springs are usually perceived to improve handling; do these tiny adjustments really make a difference? There's not an easy answer, especially for the casual driver looking for small gains, but the idea of having a Mustang that can blast through some of the hardest corners on the planet with ease is the dream of many sports car enthusiasts, and Steeda's ball joints allow you to reach that potential.
