Okay, bad pun alert. This is a semi-technical piece, from somebody with little or no technical expertise. Feel free to comment, and correct. Here goes.
Suspension. Gotta have it. Keeps the car from resting on the wheels. Like any other part of a race car, it's gone through a lot of changes. Back in the day, when race cars were cars chopped down for racing, the original suspension usually kept on providing its original service. Leaf springs and shock absorbers.
A prime example of '60's era racing technology, as built by Jim Parris of Groton, NH. This car was soon given the number 30 by its next owner, "Hard-Luck" Harold Hannaford.
Out in New York and the midwest, where there were huge crowds and a lot more money, things progressed a lot quicker. I was fortunate enough to see the cars made out of pre-war coupes and sedans with their fenders removed. On tracks that allowed it, a Jeep or International Scout frame was a popular upgrade. Soon, the old steel bodies became the only link to the cars raced after World War II. Even they began to give way to fiberglass replicas. Eventually, the bodies completed their evolution to flat panels of steel or aluminum rivetted to the chassis.
During these final transitions we began to see a beast known as a "bar car," meaning torsion bar suspension. In an over-simplified nutshell, this is a suspension system based not on a bending spring, but on a twisting bar. Torsion bars have been around since the 1920's, and were part of Ferdinand Porsche's original ideas for the car that came to be known as the Volkswagen. Torsion bars have several advantages, including easy adjustments, relative simplicity, and they were cheap to boot.
Alan Larter in a late-80's "Bar Car."
Another suspension system that became popular around this time was known as the "four-poster," using coil-over springs. This is, as the name suggests, a coil spring with a shock absorber in the middle. This is the type of suspension used in Nextel Cup racecars. A variation can be found in Champ cars and Formula One. It's a bit more expensive and complex than torsion bars, but also appears to be superior.
Doug Murphy, of Center Harbor, NH with his "Four-poster."
Both systems are in common use these days in dirt track racing, all the way up the ladder. Still, that has not kept creativity from being expressed. In the late '80's and early '90's, Jack Cook of Moultonboro started using a single transverse leaf spring made of fiberglass. I recently found out that this probably came from a school bus. Not one of the regular types, but those square ones with the flat nose that look like a loaf of bread going down the road. It worked very well, but I've never seen it used by anyone else.
Another alternative was tried by Buck and Big Bill Moses on his #15 car about the same time. They tried using an independant rear suspension out of a Corvette. It worked very well, but was too fragile to be used on a dirt track. The funny part of that was that they were still running a flathead Ford V8 at this time.
All this was done in the name of keeping the wheels on the ground. If you watch a Strictly Street or 4-Cylinder race, especially if the track's a little rough, you can quickly see what a disadvantage leaf springs and shocks have. All the wheel bounce, especially on the rear-wheel-drive cars, is almost non-existent in a Modified or Sprint.
