Engineering Oddities: Audi “UFO” brakes
[dropcap style=”style1″]T[/dropcap]he history of the automobile has been a history of innovation. Throughout the many decades of automobile production, cars have been the testbed for many engineering ideas and principles. Some things have stuck and became mainstream, but many more ideas have been applied and then scrapped for one reason or another. Sometimes because of budget or production strain, sometimes out of redundancy or necessity, and sometimes because it’s a concept that never truly worked in the real world.
Many times we hear of things being “ahead of their time” concepts that are truly innovative and forward thinking, but never fleshed out because the technology was in its infancy or there were too many teething problems as it were in production and application. One concept that wasn’t necessarily radical, but maybe a little too complex was Audi’s inboard caliper brake system later known as “UFO brakes”.
UFO brakes graced Audi’s top models of the latter eighties and up until the mid-nineties. They could be found on all V8 model cars, C3 gen 200 cars, and even the legendary UR S4. Production ended by 1995.
While an inboard caliper design wasn’t revolutionary or spectacularly innovative, it was a design seldom practiced, a lesson Audi was to soon find out. An internal brake caliper works almost identical to the standard external caliper, using the same principles of two pads pressing against the surface of a rotor to create friction, thus stopping power. The principle of an internal caliper, however, is tighter packaging than a conventional external rotor and disc. The result was improved braking in a smaller external assembly. While surface area remained identical, the swept area is larger and acting as a larger rotor mostly because it is a larger rotor. Because the rotor is positioned outside the caliper, a large flying saucer-like casting holds the rotor in place hence coining the term “UFO brakes.”
Audi’s reasoning for using such a setup, was to improve braking on their evolving sport sedans while still retaining 15’’ wheels for driving comfort. What was a totally feasible theory and practice ultimately turned out to be unpractical. While as a whole the design improved cooling, the design was also susceptible to warping rotors in stop and go traffic. Complexity, as expected in an Audi of such vintage, also strained owners and dealers while parts costs were double the traditional setup. By the mid-nineties, Audi had all but eliminated the system on its cars, and convinced owners to convert their systems to traditional ones. The conversion though, was just as costly if not more, and one of the many reasons owning an Audi in the late eighties was one of the most expensive automotive endeavors.
While most cars ended up converted, there are cars that can still be found using this innovative braking system, even if only optimistic. Honestly, despite being a failure for Audi, the idea did get use in other applications, such as with some Buell motorcycles, and it is still a very forward thinking idea. An applause for a quirky idea from what was a very quirky company.