In the last edition of Project DC2, we greatly improved our car’s suspension by replacing the ancient worn out Koni Yellow shocks with some state of the art street KW Suspension Double Adjustable Variant III coil-overs. When paired with a stock front anti-sway bar and the excellent Comptech rear anti-sway bar that came with the car, we had a well-balanced combination that worked pretty well on the track and the street.
All was good, but we wanted to go through the entire suspension and replace all of the old and well-worn rubber bushings in the car with new, hard polyurethane parts from Whiteline. This would bring our suspension up to snuff with the current best stuff out there.
The hard urethane bushings would hold our alignment true even under hard cornering and braking loads anticipated from our upcoming wheel and tire upgrades. They also greatly improve response to steering input by eliminating flex.
Like all of the Whiteline bushings, this bushing comes with Whiteline’s special urethane bushing specific grease which eliminates squeaking and sticksion.
Reducing flex and compliance in these bushings helps to controls toe and camber under side load and braking. The harder shock bushings also get more of the suspension motion under control of the damper. This improves both shock control and ride comfort.
The two piece construction helps make installation of the bushings a lot easier with no need for a hydraulic press.
This bushing needs to be stiff in the up and down and axial plane but have radial stiffness to control toe under side and braking loads. Some companies have solid bushings, but these cause severe bind, locking up the suspension and causing oversteer as well as a bad ride.
Whiteline’s part has controlled compliance with 4 windows in the urethane to allow the suspension to articulate with a solid ring center to keep the alignment under control. This is one of the best bushing designs we have seen for the trailing arm.
Previously, we have only recommended the OEM bushing in this location, but the Whiteline part should work well.