Project Honda Civic: ASR Rear Sway Bar Kit
By Bob Hernandez
Photography: Joe Lu
The long, winding road of upgrading suspension bits on our Project EJ Civic is getting pretty close to conclusion, or at least weekend track readiness. Variability (and therefore tunability) has been added to the car's setup with the installation of Skunk2's coil-overs and camber kits, and the super-worn stock bushings were punched or burned out in favor of newer, stiffer polyurethane replacements by Energy Suspension. We also secured the forward Suspension Techniques stabilizer/anti-sway/anti-roll bar and today we finally get to the rear bar, sourced from A Spec Racing (ASR).
|The A Spec Racing rear stabilizer bar kit for the EJ Civic looks high quality, with copious amounts of CNC machined parts. The setup also uses Aurora spherical bearing end links.
Last time we just touched on what a good sway bar can do, namely increase body roll stiffness; it does this by transferring force from one side of the vehicle to the other. In general a sway bar connects to the lower suspension arms and passes through pivot points under the chassis.
To understand better how one works, imagine a car in a turn and how the suspension loads up; the body rolls toward the outside of the corner and in doing so compresses the outside suspension, while the part of the body on the inside of the turn rises up. Too much body roll can negatively influence traction and steering.
|The ASR kit boasts plenty of variability, including two settings on the sway bar blade for stiffness adjustments.
To mitigate this phenomenon and try to keep a car flat, a good stabilizer bar joins the suspension from both sides of the car together and shifts some of that outside movement to the same component on the inside. As the lower part of the suspension moves up relative to the chassis, the roll bar connected to it tries to lift the same component on the other side by the corresponding amount. The inside suspension effectively becomes a fixed point and the bar twists along its length because the end is anchored in place; it's this torsion that provides the resistance to the suspension's movement.
|Looking at how the hardware fits together before we put it on the car, the rear sub-frame wall will get sandwiched between the top two layers of machined plates.
While the absence of a stabilizer bar could lead to issues with body roll in our Honda, too much bar can mean a loss of independence between suspension members on both sides of the car. Ideally, the setting we want is one that reduces roll but doesn't compromise the car's road-holding ability; the rear bar also needs to be properly balanced with the car's newfound front roll stiffness thanks to the front ST bar we installed last time.