Description
SPL Parts 2012+ BMW 3 Series/4 Series F3X Rear Upper Control Arms is a chassis-specific suspension upgrade engineered for drivers who want more precise geometry control from 2012+ BMW 3 Series/4 Series F3X. SPL Parts focuses on competition-grade suspension and alignment hardware, combining in-house development with U.S.-sourced materials and precision manufacturing for demanding street and track applications.
This upper suspension link replaces the factory arm with a more precise component intended to improve wheel-location control and, where adjustable, expand the usable alignment range. By reducing unwanted bushing movement, the upright follows the commanded geometry more closely under lateral load, helping preserve camber and toe behavior through fast transitions and sustained cornering.
Why it matters: On this application, the goal is to keep the tire and upright closer to the intended alignment as loads rise, giving the driver a more repeatable platform for braking, turn-in, mid-corner balance, and power application. The additional setup range is useful for lowered cars and wider tire packages that need alignment targets outside the factory adjustment window.
After installation, recheck fastener torque and alignment after the initial heat cycles or track use so the setup remains repeatable.