Air Ride Suspension Systems - CHP Insider

Air springs are to suspension systems what vacuum-secondary carbs are to engines. Catch a glimpse of vacuum-secondaries under the hood of a hot rod and you'll automatically assume the motor's a turd. Real men want full throttle right now, baby, and dig carbs that hit hard! Never mind the fact that vacuum-secondary carbs can easily make as much peak horsepower as their similarly sized mechanical-secondary counterparts without sacrificing streetability. Likewise, witnessing a car that can alter its ride height at will elicits a similar knee-jerk response. Air suspension is for poseurs, not racers, so it has no place in your musclecar, right? Not if Air Ride Technologies has a say in the matter.

The company has developed a habit of making converts out of skeptics. Not just any skeptics, but pros who happen to be among the best road racers in the country. Air Ride enlists big-time racers such as Boris Said and Scott Pruett-two guys who race alongside the likes of Jeff Gordon and Tony Stewart-to test its products, and the feedback from the harshest critics around has been overwhelmingly positive. Common sense says that if it impresses them, it will probably impress you too. So how does it work, what are its benefits, how do you tune them, and how hard are they to install? We talked with Bret Voelkel to find out, and we quizzed him on other assorted suspension design topics as well.

Spring Rates
Whether a progressive-rate spring or a linear-rate spring is better for hard-core cornering is much debated, but there is a time and place for each. According to Bret, the only argument against using a progressive spring rate would come from the potential tuning headaches it creates for novices. "A progressive spring rate is just one more tuning variable to throw into the mix when it comes to overall suspension tuning, but if you have an adjustable suspension and the know-how, then that variable is easily manageable," he explains. When it comes to air springs, they can be made to be perfectly linear or extremely progressive. Air Ride typically uses double-convoluted air springs in the front suspension since it's highly leveraged. "This is because the front wheel always travels faster and longer than the air spring and shock, so we want the air spring to gain spring rate much quicker to properly control the oscillations of the vehicle. In the rear, we typically use a sleeve-style air spring with a nearly linear spring rate. Since the rear air spring is more of a direct load application that moves at the same rate as the axle and wheels, it needs more travel and a softer spring rate throughout its travel."

Components
"An air suspension is viewed as being more complex than a mechanical suspension, but in reality, the only additional part is the compressor system. The coil spring is replaced by an air spring, and you still need a shock absorber, just like in a traditional suspension. A compressor system can be as simple or as complex as the customer desires. A simple compressor system would consist of a compressor, a tank, air lines, and an inflate/deflate valve for each air spring. An automatic leveling system would add ride-height sensors and some sort of electronic controls to process the data generated by the leveling sensors. This is an area that has a lot of variables and could fill an entire article by itself."