SPL Parts Rear Lower Control Arms (2008+ WRX, 08-21 STI, 2013+ BRZ)

SPL adjustable Rear Lower Camber Arms (RLL) for the GR86/BRZ/WRX allow for adjustable camber, track, and installed motion ratios while significantly reducing the unwanted dynamic alignment change and binding that occurs with rubber or polyurethane bushings. The lower arm also handles the forces transmitted through the springs, shocks, and sway bar. By increasing the strength (rigidity) of the arm and using a spherical the rear suspension will have improved response, better lateral grip, and provide clearer feedback to the driver.

Adjustable Motion Ratios

The three position mounting holes for the sway bar endlinks and shock mount allow you to adjust the mounting points to prevent endlink binding and quickly adjust motion ratios to change spring and sway bar effectiveness. Simply put, it's like having adjustable spring rates without a spring replacement. For example, a 6.0 kg/mm (336 lbs/in) main spring could act as a 6.8 (380 lbs/in), 6.0, or 5.2 kg/mm (294 lbs/in) spring, giving +/- 13% of adjustability. Likewise the sway bar endlink can be installed to act like a 0.5mm larger or smaller bar, so an 18mm bar would act like an 18.5mm, 18.0mm, or 17.5mm bar depending on setup (endlink geometry permitting).

Unrivaled Adjustability Range

The large-diameter chromoly double adjuster and 5/8" (15.8mm) rod end allows for up to 1.375" (35mm) of total length adjustment, a 50% increase compared to many other options on the market.

Benefits

• Large Range of Camber and Motion Ratio Adjustability
• Lightweight: 3.57 lbs (1.62 kg) per Arm (17% Lighter than OEM)
• Eliminates Camber Loss to Bushing Deflection
• Improves Suspension Response and Driving Feel
• Easier, On-Car Adjustment + No Jam Nuts
• Self-Cleaning, US Made, PTFE-Lined FK Bearings

Materials

• 6061-T6 Aluminum Arms (Anodized Black)
• 6061-T6 Aluminum Spacers and 360º Clamps
• 4130 Chromoly Steel Double Adjuster (Electroless Nickel Plated)
• Ti-6Al-4V Titanium 1/4-20 Socket Head Allen Screws (Anodized Blue)

Easy, On-Car Adjustments

Instead of jam nuts, the SPL rear lower arms feature 360° clamps and an electroless nickel plated double adjuster to make setting the camber angle significantly easier. Simply loosen the 1/4"-20 titanium hardware and turn the double adjuster to achieve the desired amount of camber. Lastly, tighten the 1/4"-20 titanium hardware to lock it in. No more wandering alignment specs as you try to hold one end and tighten the other.

Noise, Vibration, and Harshness (NVH)

The rear lower control arm is not a significant source of percieved NVH. In fact, it's more and more common for OEMs to use sphericals in the knuckle bushing where the lower control arm mounts. The spherical rod end eliminates torsional bushing bind, resulting in a small improvement to ride quality, but may transmit a small amount of additional road noise over textured/grooved pavement.