The Racer X Fabrication 4130 chromoly front lower control arms for the 2015 - 2021 Subaru WRX / STI are one of the limited options available for adjusting camber and caster. The durable chromoly steel construction allows for simple, on vehicle, adjustment using adjustable threaded adapters and chromoly rod ends. The tubular design provides a 1 lb weight savings per side (2 lbs total weight saving) over the aluminum OEM version of the control arm. The Racer X front lower control arms retain the OEM sway bar link mounting tabs and OEM ball joint taper that is compatible with the OEM ball joint or extended RCA ball joints.
The front lower control arms are constructed from 4130 chromoly steel to increase rigidity and strength while reducing overall weight. The chromoly tubing is end formed and threaded for an adjustable threaded adapter for use with chromoly rod ends. The control arms are mandrel bent to precise tolerance and then prepared for TIG welding using fixtures from OEM data points. The ball joint end is also constructed from chromoly steel and CNC machined for an OEM fit that maintains the use of the OEM ball joint taper. The final assembly is finished with a black zinc plating to protect against the elements and provide corrosion resistance.