Words By Scott Parker
Photography Courtesy of JMS and ZPE
In the unending quest to go faster, the boost goes higher and the supercharger pullies get smaller. But, there’s a problem. Just like with tires, smaller pullies have less traction. Manufacturers do everything they can to increase belt wrap via the accessory drive arrangement, and will go wider on the pulley with 8, 10, and even 12 ribs. Despite these advantages, belt slip rears its ugly head, sometimes at the top end or even right at the starting line. JMS Chip & Performance has partnered with ZPE to provide an innovative solution called GripTEC, so you can leave the cog belts to the Pro Mods.
GripTEC Micro and GripTEC Weld are two processes that ZPE has patented, which increase the pulley’s grip. GripTEC Micro is a CNC ablation machining process that actually removes material from the gripping surface of the pulley, while GripTEC Weld is a micro welding process that adds material. These two techniques both accomplish the same goal, which is to create the most load capacity for the belts using an engineered grip pattern. According to Drew Zimmer of ZPE Inc., these techniques spread the load over the entire pulley surface rather than just a dozen or so key points.
“GripTEC Micro is a computer controlled removal process that allows us to target width and depth of patterns. We can engineer the surface with a target coefficient to increase friction against the pulley and belt to eliminate slip. Some guys are using a welding stick or arc, placing a droplet of metal on the pulley, but it isn’t consistent. Our process is repeatable, dependable, and reliable. And there is a wide range of adaptability: we have two different levels of grip on aluminum pulleys as well as steel. There is definitely a tipping point where you can have too much of a rough surface and you can damage the belt, but because our process is so calibrated, we can keep it in the sweet spot. The pulley will take the brunt of abuse before it will damage the belt with the aluminum pulley. Steel is not as forgiving, so we run less aggressive patterns.
“GripTEC Weld is a welding process where a formulated aggregate, consisting of several specific metals and non metals, is created using specific size granules. It is then applied to a part and welded (using a focused plasma) to the surface, encapsulating the targeted aggregate. This allows us to control the surface coefficient through an extremely repeatable, calibrated roughness. This process has many of the same benefits as our micro technology and adds the advantage of a more durable surface to a part as well as a high optical contrast.” When manufacturing in high volume, Drew says Micro is advantageous since it is less time consuming. Although the micro welding process imparts the same precision and end result, some still prefer it for aesthetic reasons. “Both technologies can even be mixed to create some wild looking and highly functional parts.”
JMS has exclusive distribution of co-branded serpentine pullies for a variety of supercharged applications that are treated with GripTEC Micro and GripTEC Weld. JMS says an OEM supercharger system, such as the Cadillac CTS-V or Shelby GT500, will typically see a 1.5psi gain by switching to a GripTEC treated pulley. Even on the COPO Camaro’s 10-rib Whipple supercharger system, they’ve found a .1-.2psi gain via GripTEC. And because there is less belt slip, it can actually increase the belt life.
The applications continue to widen for both GripTEC Micro and GripTEC Weld. Working with JMS, ZPE has proven the viability of these processes on the JMS Avenger and Savage series drag wheels. Beaded corners can keep the tire from spinning on the wheel just like a beadlock. This can be extremely valuable in classes that do not allow beadlocks. Just think of any metal surface that needs greater friction to perform better. Drew said that it might even prove useful on a cog pulley to extend belt life and reduce noise (not for grip) as well as metal-to-metal surfaces. We can only wonder what’s next.