Since getting your muscle car to carve corners and rip up autocross events has become the hot new thing, we wanted to explore one of the more common questions: "How big of a sway bar do I need?"
First of all, let's explain what a sway bar is. A sway bar is a suspension component used to reduce body roll during a cornering situation. It does this by tying the left and right lower control arms together with two pivot points on the frame. When the left and right suspension assemblies cycle together, the sway bar just pivots on the frame bushings and doesn't do much. It's when the left and right assemblies move independently that the sway bar is engaged, like when throwing the car into a corner. During a cornering situation, the outside suspension assembly is compressed up into the wheelwell while the outside assembly extends down. Since the bar is tied to the frame and to each control arm, the bar gets put into a twist and tries to equalize compression and extension in turns, thus keeping the car flat.
Armed with the basics of what a sway bar does, we are going to get into our testing. We had Super Chevy publisher Ed Zinke bring out his super-clean '64 Chevelle convertible as the test mule. The car features Global West suspension front and rear. It rolls on 15-inch Rally rims with P215/60R15 tires set at 33 psi at all corners. The car had a factory front sway bar and no rear bar.
We also invited suspension guru Doug Norrdin from Global West Performance and asked him to bring an assortment of sway bars for Ed's car, along with all that suspension knowledge stuck in his brain. Norrdin brought two different front bars and two different rear bars for comparison. To keep the driving consistent, we had our in-house West Coast hot shoe "Quick" Nick Licata pilot the car through the 420-foot slalom. Now that you know the parameters of our test, read on to see the results.
Here are all the bars we tested. Starting at the front and moving back, we have the stock
* 6.73 seconds = 42.7 mph
* Stock front bar
* No rear bar
Before we added anything to Ed's combination, we needed to get a baseline.
The front suspension consists of Negative Roll upper and lower tubular control arms, tall
The rear has adjustable upper and tubular lower control arms with an S-60 coil springs fro
The car has a stock 15/16-inch solid bar that is rated at 156 pounds. During the test the