2008 Subaru WRX Project

TEIN USA handled the installation of the bushings. The front lower control arms were removed and all bushings were replaced. On the rear of the arm is an eccentric bushing that can be used to adjust castor on the front suspension by pushing the entire arm (and upright lower mounting point) forward or backward. The same bushing can also be shimmed with an anti-lift elimination bushing that lowers the rear of the front lower control arm and makes it level with the car. Leveling the front control arms take out the binding effects of the torque reaction as the arm swings (called anti-lift) and allows the car to dive linearly under braking for better predictability and weight transfer communication. The trade-off with the anti-lift bushings is the excessive NVH transferred through the floor. The location of these vertical bushings is just in front of the front footwells so the discerning driver will feel every little bump.

On the multilink rear suspension, Super Pro has bushings for every single control arm, antiroll bar endlink, and upright. We replaced every bushing except the stock pillow-ball bushing on the upright that connects to the rear lower arm. Super Pro also provides a nice tool to help pull the stock rubber rear upright bushings without having to remove the upright. The squishy transmission support bushings were also replaced and the rear subframe bushings were filled with Super Pro polyurethane inserts that fill the voids designed in the stock bushings to give longitudinal compliance. We like the fact that the top and bottom half of these subframe inserts do not actually touch each other when the vehicle's weight is sitting on the subframe. This reduces the transmission of vertical shock through the rear floor section but still reduces compliance in the horizontal plane. The subframe inserts were designed to be installed without the removal of the entire subframe.

One key trick was to tighten all the control arms with bushings installed only while the car is sitting on its own weight, or under 1 g conditions. This ensures that each bushing isn't already under twist or tension at its static state, which can actually effect your overall wheel rate to be mismatched with the dampers rebound damping characteristics.

Whiteline Automotive, also from down under, and their North American distributor, Global Performance Parts, finished off our setup tweaks with new polyurethane steering rack bushings, a front lower subframe brace, front bumpsteer tie-rod outer ends, front control arm ball joints, and a rear antiroll bar brace. The rack bushings and bump steer adjusters are designed to help further improve steering feel on the WRX, which, although already a huge improvement over previous-generation WRXs, still could be helped. Whiteline provides the tools to remove the stock driver side-rack bushings, which are pressed in, without having to pull the rack out of the car. More credit for the Aussies for their consumer-friendly products.