When the ultimate goal is winning, most racers realize that the quest for improved performance is an ongoing process. Innovation and constant improvement are commonplace in motorsports and knowledgeable racers understand that they need to stay informed and committed to remain competitive. While some are often looking for a “quick fix” or the “trick of the week”, seasoned enthusiasts realize that top-notch cars are, in fact, effectively prepared literally from literally front-to-rear and top-to-bottom. From the wheel bearings to the engine bearings, friction is one of the biggest enemies of achieving maximum performance.
One area that is often taken for granted are the wheel bearings. Whether they participate in oval track, road race, or drag racing, most racers utilize standard replacement wheel bearings that are simply packed with their favorite brand of grease. Any race car should roll very easily when pushed in a straight line, and regardless of the results, there is always room for improvement. Refining practices initially employed by NASCAR cup teams, DRP Performance Products developed a full line of low-drag hub components that are specifically designed to reduce friction and lower temperatures, allowing the wheels to turn more easily, and effectively enabling racers to deliver more horsepower to the track.
Each product has been subject to extensive research, development, and testing utilizing a special in-house hub dynamometer, according to DRP’s Lynnie Doughton. Doughton states that hub dyno testing allows monitoring energy exerted, load, speed, and temperature, all in the quest to reduce wheel bearing drag. The unit additionally allows DRP to perform “A” / “B” style comparative testing, so that bearings, seals, and greases may be evaluated under identical conditions, critical to proper product development.
The main component in DRP’s low-drag hub program is the usage of an adjustable bearing spacer, marketed as the “Hub Defender”. The patented, one-of-a-kind product installs between the inner and outer wheel bearings, and allows precise adjustment of the distance between the bearings. When properly adjusted and installed, the spacer allows the spindle nut to be tightened completely and bearing load distributed equally across both bearings, preventing any bearing pre-load and effectively reducing bearing temperatures by up to 100°F. Installation makes such a significant improvement in reducing wheel bearing drag that Doughton states that racers “will instantly feel the difference by just pushing the car in the shop”.
Installation is relatively straightforward: The hub is initially installed with the bearings and spacer in place, yet without grease. After the spindle nut is completely tightened, bearing end play is checked, the spacer is removed, and its height adjusted as required until the specified end play is achieved. Spacer height may be measured simply with use of a micrometer or dial caliper. Once the final adjustments have been made, the spacer set screw may be sealed with Loctite to prevent any unwanted changes.
During the set-up process, it’s important to keep the hub, bearings, and spacers together as sets, and if replacement of any component is performed, the spacer will require re-adjustment due to minute differences in component sizing. Bearing spacers are offered by DRP for a variety of popular applications, and are sold complete with detailed set-up instructions.
It is possible to achieve additional reduction in wheel bearing friction by utilizing special, low-drag bearings. Doughton states that DRP’s low drag bearings are subjected to a proprietary, five-step process that combines the use of special chemicals and a vibratory mill that reduces the existing peaks and smooths the surface, ultimately reducing bearing drag and hub temperatures.
Hub drag may be further reduced by employing DRP’s Ultra Low Drag (ULD) or Air Gap (AG) grease seals, according to Doughton. ULD seals combine a lightweight aluminum housing with a full PTFE sealing element, while AG seals deliver “air curtain” protection, keeping dirt and contaminants out, while eliminating any seal drag.
Wheel bearing performance may be further enhanced with the use of DRP’s Ultra Low Drag Wheel Bearing Grease. Manufactured by Kluber Lubrication, Doughton stated that it performed up to 60% better than traditional wheel bearing greases during hub dyno testing. DRP recommends that when packing bearings, it is only necessary to fill every other roller bearing cavity, resulting in a 50% total bearing pack. Bearings that are over-packed will cause increased drag and higher bearing operating temperatures.
For ease of part selection and installation, DRP offers all-in-one, low-drag hub kits for a wide variety of applications that include all of the necessary components for a single hub: an adjustable hub spacer, low-drag inner and outer bearings, and a low-drag hub seal.
Utilizing DRP’s low-drag wheel bearing technology is just one more step racers can take in keeping up, and maybe even get a step ahead of the competition.