In the early '80s, Buddy Baker lost his chance to win at Daytona due to a broken wheel stud. The problem was brought to ARP's attention for a solution to the stud problem (the company did not manufacture the broken stud). Upon examination, even new studs showed cracks at the root of the thread. ARP addressed the problem by starting with the toughest design criteria. It calculated the load on the right-front wheel studs of a car (the most-loaded tire) running at Daytona at 200 mph (before restrictor plates), and designed a stud so one stud alone could hold the wheel. That required a new material for higher strength. ARP also added the now-common bullet-tip end and large-diameter lead-in to make cross-threading virtually impossible. Finally, the company applied a baked-on lubricant, which significantly speeded up pit stops (up to two full seconds). The result was a big step in safety and performance, and a tribute to ARP's philosophy of designing fasteners for their specific applications.

In another case, ARP's final solution to a head-cracking problem was the development of a stud kit that incorporated four different-diameter studs, two different materials, and three different tensile-strength levels. The solution was complex, but the problem was solved.

Whether it be a Winston Cup wheel stud, a late-model rocker-arm adjuster, or a head stud, fastener manufacturers strive to build the best piece for a specific application. But manufacturing the fasteners is one thing. Their proper use and installation are another.

Knowledge Is King
"Understanding how fasteners perform optimally is absolutely essential for a race team-too many things are riding on the quality and performance of fasteners. Engine and chassis performance, race results, costs, and most importantly, safety, are all at stake when choosing and installing fasteners," says Florine.

Ironically, it is probably more difficult for the Saturday-night racer to understand all the technology and applications than a Winston Cup crew member. At the Cup level, each crew member has a specific area of expertise: engine, drivetrain, suspension, and so on, and his concentration is in one area only. But for most racers, the crew chief and driver must often be aware of every application, since they are involved in virtually every facet of the car's operation. How does one learn all there is to know about all these fasteners, as well as their correct application and installation?

The answer: knowledge and experience. Like everything else in racing, information is the key to knowing how to get the most out of your equipment.

"We are always providing information to racers through trade shows, seminars, our catalog, and our tech line. It is in our best interest to educate racers to the highest level possible," says Florine. "Fasteners are cheap insurance. Their proper use is essential to quality race cars."

The knowledge it takes to become an expert in fastener technology and application would take a complete book to present, but Florine had these important points to make in choosing fasteners and installing fastener hardware:

First, get the proper fastener for the proper application. That means you don't underkill or overkill the fastener application. Having a fastener that can't meet strength demands can have obvious ramifications, but having ones that don't tighten properly (require extreme torque to tighten), for example, can lead to crushing the base material (aluminum). Each connection on a race car has its own performance requirements, and each fastener must be chosen to meet those requirements.