[h=2]SCCA: How it’s made[/h] Thursday, 02 June 2016


Philip Royle (words and images)
This story originally appeared in the July 2016 issue of SportsCar magazine, the official member magazine of the Sports Car Club of America. A subscription to SportsCar magazine is one of the many benefits to joining the SCCA – the other being the ability to compete in any of the more than 2,000 competition events the SCCA sanctions year round, from autocross to professional road racing. Kick start your motorsports dream by heading to Main - Sports Car Club of America and joining now.
We tour a manufacturing facility we didn’t know existed and learn that racecar springs, dampers, and swaybars are made in a way we didn’t know possible
The door opens on an otherwise ubiquitous looking warehouse in Corona, Calif. – a warehouse you might otherwise assume is simply a distribution hub for this international suspension company – and we step inside. But while this massive building does house products ready to ship, it's also where Eibach Springs manufactures the vast majority of its springs, swaybars, and coilover systems that customers purchase in the U.S. It's also the starting point for the question that brought us here: How are automotive springs manufactured? The answer, we discovered, is somewhat surprising.
While an increasing amount of the manufacturing process is automated, a significant portion requires hands-on interaction by Eibach's staff, both in setup and quality control. (Below: Once production is complete, quality control uses a dyno to check the springs meet Eibach's standards.) On top of this, we discovered, there are a lot of preconceived notions about spring manufacturing that are either no longer true, or perhaps never were.
For starters, you won't find a massive oil bath where springs are dumped after being superheated and bent into their springy form. To be honest, we were expecting a medieval foundry in this regard. But, while you might see that at some point in Eibach's manufacturing process, it's the exception rather than the rule, and probably doesn't apply to your competition or street car parts at all. The realities of spring manufacturing are a little less flashy, but just as effective.
"A spring's life starts as raw steel," explains Mark Krumme, who heads the marketing department for Eibach, and is also a bit of a car nut himself. "We keep about 600 metric tons on hand at all time. Since we only order from a few suppliers for the sake of product consistency and quality, we have to keep at least a six-month supply of wire on hand."
Standing amid these massive bales of raw wire is somewhat frightening, as the unimaginable amounts of potential energy wound into tall circles of steel is intimidating. As we walk through aisle after aisle of these steel bales, Krumme assures us we needn't worry – a multitude of precautions are taken to keep the entire process safe.
"The wire then goes over to a proprietary Wafios winder, a machine that was designed to our specifications," Krumme continues, noting that the same machines that wind Eibach's street springs also wind intricate race springs for both your average SCCA racer and NASCAR.
The now recognizable automotive springs then move to a massive tempering oven, which looks like a stumpy, exceptionally reinforced shipping container. Once inside, the springs are heated and cooled, setting the steel into its new shape. The springs then head to finishing, where a chamfer can be added or the ends ground, depending on the application.
Shot peening comes next. "This removes the outermost layer of material and is basically like a forging process to strengthen the material," Krumme explains. "After this, you have a much stronger spring."
From this massive industrial machine, a box of springs is wheeled about 20 feet to the presetting department. There, a person takes each spring, places it in a comparatively small machine, and compresses the spring until the coils bind – otherwise known as hitting block height.
"This basically sets the height of the spring for the duration of its life," says Krumme. The spring loses a small portion of its height here, but that's all worked into the equation in the engineering.