Hendon Publishing - Article Archive Details

Print Article Rate Comment Reprint Information

DBA Police-spec Rotors

Written by Ron Hix

What are the most important safety features on any emergency vehicle? We can debate what is number one, but certainly tires and brakes are in the top 10. During the past five years, braking performance has received a lot of attention. This makes sense. Police vehicles have recently become much more powerful, and the handling has improved to allow for much higher speeds in most situations. However, horsepower and handling have to be controlled to be effective. Performance braking is a major controlling factor. “Go” is no good without “stop.”

There is no room for compromise in the area of officer safety, and that means not tolerating less braking performance. With budget constraints affecting every department, fleet and maintenance supervisors are looking at all options to keep officers safe while effectively managing resources.

Additionally, testing and certification criteria for police and public fleets changed in 2008, which put additional emphasis on safety, wear, heat dissipation, effectiveness and brake fade high-speed performance. This has resulted in attempts to purpose build replace disc brakes for law enforcement and emergency vehicles. In some cases, the new performance disc brakes have a racing heritage that has historically focused on safety, performance and durability.

There have been numerous designs and materials proposed and offered: drilled, slotted, drill and slotted; straight vein, curved vein, pillar; high carbon content, low nickel content; cryogenic treating; heat treating. Some have a singular advantage in one area, but few offer the best overall combination of design and materials. Regrettably, some products purporting to be purpose built are no more that standard OE replacement products with added modifications.

One brake component manufacturer has improved and adapted its successful disc brake design for law enforcement and emergency vehicles. For more than 40 years, Disc Brakes Australia (DBA) has been a leader in high performance, racing and OE disc brakes throughout the world.

DBA, with headquarters and manufacturing facilities in Sydney, Australia, is a family-owned company managed by brothers Phillip Joseph, managing director of the Australian facilities, and Mark Joseph, sales and marketing director. DBA has its North American headquarters in California and a brake component warehouse in Michigan.

The DBA team has successfully taken its racing heritage and melded it into practical day-to-day applications. Being “track tested” is another assurance that the DBA daily use products exceed the expectations. The experience DBA has in high-speed circle track racing, road racing and endurance off-road produces a product for all types of severe duty. DBA has infused the right combination of variables based on successful designs and applications to produce a world class performance product for law enforcement and emergency vehicles.

Control of the variables is the key. Because DBA owns its own foundry and manufacturing facilities in Sydney, it has 100 percent control of materials and process. DBA manufactures its range of advanced brake rotors to the automotive industry’s leading standards such as ISO 9001, QS 9000 and TS-16949 quality certification.

The DBA proven design incorporates three distinct elements. The first is a specific iron recipe, XG-150, which is specifically formulated for the demands of high performance law enforcement vehicles. The recipe results in material for performance, durability and reliability.

The second is Thermo Stability Profiling. Through heat treating, each disc brake allows the brake rotor to handle more heat, remain more stable and reduces brake fade. The DBA Police Pursuit Series brake rotors incorporate Thermo-Graphic Temperature Monitoring. The rotors have paint markings that change color at specific temperature thresholds. By monitoring the markings, fleet managers can check their braking performance quickly and easily.

Kangaroo Paw Vanes

The third DBA design advantage is its patented XF-144 ventilation system consisting of 144 diamond and tear-drop pillars (unlike veins in other rotors), which provide improved cooling and resist disc warping. Every time the brakes are used, pressure is built up through the braking system. The force applied at the brake pedal is multiplied at the disc rotors, creating friction and extreme heat. The extreme heat can cause disc rotors to warp, distort and in some cases fail.

Standard rotors have air paths for cooling inside the rotor. Traditionally, heat is removed as air flows through the rotor, passing between straight “cooling vanes.” However, the straight vane design does not provide the ideal conditions for heat to be dissipated and tends to allow an unwanted ballooning effect. Some rotors may have directional vanes, which means the air flow works when the rotor turns in only one direction. Switching the left and right rotors will end the air flow and the cooling.

The DBA rotors use the patented Kangaroo Paw design for improved air flow. The patented XF-144 Ventilation Design features 144 precisely positioned diamond and tear-drop pillars. The pillars create greater strength, reliability and a more efficient cooling system. Greater surface area means more rapid heat dissipation.

Cool air flows in from the center of the disc, while hot air is forced to the outside of the disc, regardless of rotational direction. The pillars provide greater strength across the disc rotor and reduce the tendency for disc distortion. More efficient cooling improves brake pad and disc rotor life, and it helps reduce brake fade.

That results in more brake system cooling and better rotor stability during severe use. DBA Police Pursuit Series disc rotors will quickly remove the heat, cool the discs and return to optimal operating temperatures, ready for the next braking application—without a soft brake pedal.

Case Study

A DBA test is underway at the East Point, Ga., Police Department in the Atlanta area. The initial field test results are outstanding. The department’s hot-seated (24/7) patrol car was averaging between 6,000 and 8,000 miles per set of disc brakes. Currently, the DBA Police Pursuit Series rotors have over 48,000 miles on them. Performance has been enhanced with improved stopping power, brake fade reduction and extended life. Down time and per-mile vehicle cost have been greatly reduced.

DBA is confident that any law enforcement and emergency vehicle application will likewise see results of four to six times the rotor life the vehicle is currently getting on a set of OE disc brakes. Other tests in multiple law enforcement applications are producing similar
performance results.
 
Ron Hix is the fleet sales manager for Disc Brakes Austrialia-USA and may be reached at ron@dbausa.com.

Published in Police Fleet Manager, Nov/Dec 2010

Rating : 9.7


Comments

Comment on This Article

No Comments


Related Companies

Disc Brakes Australia
 

Related Products

Brake RotorsBrakesDisc Brakes Australia Police-Spec Rotors
 

Article Images

Click to enlarge images.

 
Events and Tradeshows: LAOPFMTRPSIT
Latest News: LAOPFMTRPSIT
 
Close ...