.boB

A sway bar (really, anti-sway bar) ties the two sides of the suspension together.

In a turn, the CG shifts to the outside of the curve. Instead of being in the center, you have more weight on one side of the car than the other. Imagine what happens to the suspension if two big guys sit on your left fender. That causes the outside suspension to compress up into the chassis, and the inside suspension to droop out of the chassis.

Now all the weight and traction is on one side of the car. That's a bad thing for a lot of reasons, but mostly because 2 tires won't provide the same traction as 4 tires.

The sway bar ties both sides of the suspension together. It essentially uses the inside tire/wheel/suspension to act as a counterbalance for the rest of the car. It prevents the inside from drooping, and helps keep the weight more towards the center of the car. That's why you sometimes see race cars lift the inside tire off the ground.

The bar acts sort of like a spring, and resists twisting. Think of a stock Dodge torsion bar suspension. The thicker the bar, the bigger the spring rate, and the more resistance to twisting. There's very little differance in overall ride quality between a medium and heavy bar, or a light and medium bar. Since the suspension is tied together but not restricted, it allows the normal up and down movement of the suspension as a whole. So when you hit things like expansion cracks and dips, the suspension is allowed to do it's thing.

You can get some increased harshness if one tire is on smooth pavement, and the other is taking big dips and jumps. But a good street bar set up will compensate for a lot of irregularities and still give you a nice ride.

For a race car, the springs and shocks provide the overall suspension charectoristics. The sway bars are used for fine tuning. On a daily driver/street car, it's kind of the opposite. Use relativly soft springs and shocks with lots of range, and then use a large stiff sway bar for control.

phutch11

.Bob,

Well said.

There are some finer points of how dynamic loading works and how a swaybar transfers dynamic loads front to rear that you likely intentionally left out, but an excellent summary.

Big bars and soft springs are the way to go for a great ride and outstanding handling.