INTERESTING ENGINEERING: Audi’s UFO Brakes

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The Lamborghini Urus has 17.32″ brakes, currently a world record. Yes, this is not only an absolutely preposterous brake size but is also a marvel of modern engineering. This isn’t the first time a VAG product pushed the boundries of brake tech though and it certainly won’t be the last. While the Urus has a relatively tame but massive brake design, VAG has delved deep in the avant garde of the braking world.

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What may be their peak of avant garde? The outer limit’s of VAG’s avant garde brake designs might be the Audi 200 20V Quattro’s front brake design which was originally designed for their S-class fighting V8 Quattro. Nicknamed the UFO rotor, the design was officially called an internal brake caliper and was produced by ATE. It was a standard disc brake system that had been inverted to have the caliper located inside of the diameter of the brake rotor. So, what on earth caused Audi to design this ridiculous looking brake rotor? Braking performance.

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When Audi was developing the V8 Quattro in the late 80’s, the 17″ wheels were just about the biggest wheels you could find on a production car and even then they were few and far between. Brake rotors realistically couldn’t get far past 12″ on even the highest performance cars, the 1987 Porsche 911 came with at most an 11.1″ brake rotor which is just shy of the size of the standard brake rotor on a modern Mini Cooper. Audi wasn’t willing to put a 17″ wheel with a rock hard sidewall on their cars so they looked for a solution to their quagmire they had put themselves into. The solution was a thicker rotor that could absorb more heat and that heat absorption leads us to Audi’s UFO brake.

UFO Rotor Breakdown

By placing the brake rotor inside the brake that allows that few inches of extra space to be used for more brake rotor surface area. To make this happen Audi had to make a huge wrap around hub that extends from the center of the steering knuckle to the outer edge of the brake rotor. Conveniently, this also allows the brakes to effectively have a larger heat sink that extends beyond the contact patch of the pad and fills the area up to the wheel with extra material that can absorb heat.

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After ATE and Audi finished prototyping the design, Audi was able to fit a 12.2″ brake rotor behind a 15″ wheel with less than 3″ of space not dedicated to brake rotor diameter. The modern Lamborghini Urus has to run a massive 21″ wheel to fit those 17″ dinner plate rotors with twice as much space dedicated to the caliper and not allowing additional heat absorption.1988 audi_v8_1
Audi was able to prove the world wrong and fit a 12″ brake behind a 15″ wheel and answered a question that nobody was asking, but was it all worth it? Well, yes actually. The Audi V8 Quattro was able to stop from 60 MPH in 120 feet during it’s 1989 Motorweek review, for comparison the Lexus LS400 did it is 121 feet the next year and that was with every bit of Toyota’s vast R&D department behind it. Surely, this technology was going to change how we design brakes forever.

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It did until it didn’t. While the UFO rotor made it onto the 200 Quattro, V8 Quattro and Ur S4, by 1995 brake and tire technology had advanced to make this design unnecessary. With larger wheels becoming more commonplace and lower profile tires becoming more acceptable, Audi was able to increase the size of the wheels it was fitting cars with and reverted to standard rotor designs.

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Audi could have continued to utilize this design but it wasn’t without it’s issues. The biggest issue for Audi was the cost to make these. With a standard brake rotor, one size can fit multiple models across several makes, a cast for a specific diameter and hub size could be made and the PCD can be drilled to exact specifications with minimal tooling changes. With this completely different design, that wasn’t possible. Audi was responsible for the brunt of the entire cost of ATEs production for these rotors. What cost Audi an exorbitant price to make was reflected to parts costs to retail customers, while a standard brake rotor could be had for around $100 over the counter at a dealership, these were a whopping $550.

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Additionally, the UFO rotors were effective but didn’t hold up well in the real world because they were very susceptible to warping. The warping wouldn’t occur during spirited driving but became a massive issue in daily use. A quick stop and holding on the brake, as one does at a stop light, would cause the rotor to develop a hot spot because half of the rotor would cool faster than the other half. As metal expands when it is warm the rotor would bend slightly where it was cooling faster, thus creating an uneven braking surface and a vibration while braking. This was extremely common and it’s almost impossible to convince owners to change their driving habits from what they were used to doing.

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In a 1995 TSB, Audi advised that production was ending and, after the stock was gone, that cars be converted to standard rotors if the customer wanted official VAG parts. That was the end of the Audi UFO rotor and today the old stock is becoming harder and harder to find. Unless someone is absolutely a purist about preserving their old Audi, it’s very hard to justify keeping these strange brakes. The cars that came with these rotors are on the cusp of becoming collectible and are considered just another old car to a lot of owners. Most people with these brakes on their cars are either living with warped rotors or biting the bullet and doing the conversion. Occasionally sites like ECS Tuning offer a small stock of NOS rotors but it is rare and you’re more likely to find some being sold on the private market.

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Unfortunately that’s just the cost of reinventing the wheel. It was a noble effort but a technology lost to time. The automobile world’s greatest innovators rarely see any profit from their innovation. The most innovative companies in automobile history have ended in failure. Bugatti, Citroen, Dusenberg, Bricklin, DeLorean, the list is endless. Companies like VAG and Tesla are only able to operate the way they do because of a massive amount of investment. We often give VAG a hard time here at Carbitrage because of some of their practices but we’re always willing to give credit where it is due and this is absolutely worth noting.

40 SHADES OF GOLF

VW has gone all in with their new Spektrum Program with 40 new colors available to the Golf R and only 10 of them are variants of silver or grey.

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Photo Credit: Volkswagen Group

White, Grey, Silver, Black, Charcoal, Beige, then the same Blue and Red. Looking through the color pallet on cars from the last 15 years has been a slog. At one point when I walked onto the lot of a Mazda dealership while helping my mother look for a car, I called an optometrist because I thought I may have gone color blind. Do you remember back in the 1990s when you could buy a pink GMC Sonoma, a Teal Honda Civic, or a purple Ford Escort? Volkswagen even took it to the next level back then with their Harlequin Golf in Europe where it came in four different colors, at the same time.

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It was a golden era for car colors but it seems like everything else in the 2000s, everything got boring. Your Electron Blue Pearls and Pink Coral Micas were replaced with Desert Sand Mica and Seaside Pearl Mica, aka those generic earth tones Toyota had on everything. Yes, you could still get super cars or the occasional special edition sports car in an exciting color but that’s really where it ends.

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Photo Credit: Groupe Renault

With the exception of some Asian countries, this seems to be a very American phenomenon for buyers to stay within the monochrome scale as many European markets have wide ranging color palates available. Renault for instance has a bright blue, yellow and orange option for their Megane Sport and Skoda even allows you to have a light blue Citigo with multiple accent colors for the roof and mirrors!

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Photo Credit: Volkswagen Group

Since the recession we have seen a resurgence in exciting colors, luckily. The second generation Honda Fit had Blue Raspberry Metallic, which was arguably Honda’s best teal color and the Mitsubishi Mirage debuted with Plasma Purple, a loud retro 90’s pink hue. But even then, manufacturers have had one or maybe two exciting colors on their pallet lately but VW has gone all in with their new Spektrum Program with 40 new colors available to the Golf R and only 10 of them are variants of silver or grey.

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Photo Credit: Volkswagen Group

The new color palate has colors from Volkswagen’s past such as Ginster Yellow, originally found on the 1997 Driver’s Edition GTI, but also has new colors that pay homage to Volkswagen’s history of excellent colors. At the cost of an extra $2,500 Volkswagen will build a Golf R in any requested color on this list, they expect to have a two to four month build time until the car is ready for delivery.

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Photo Credit: Lamborghini SpA

Volkswagen also pulls some colors from their other lines like Viper Green, found on the Mk3 Scirocco and Lamborghini Huracan. With a company like Volkswagen with such far reach across the automotive spectrum, I like that they’re taking the effort to give enthusiasts the ability to choose essentially any color they want. Part of me wants to complain about the $2,500 up charge but I’m not terribly bothered by this since brands like Mercedes have been doing this for years.

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Photo Credit: Volkswagen Group

Overall it is a good thing that we’re seeing more of the color spectrum explored by automakers. Volkswagen could have very easily just said “silver, black and grey have the highest take rate so we won’t stray from that.” That is a fact by the way, that’s why you see so many non-car enthusiast people driving cars that are that color.

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Photo Credit: Volkswagen Group

I will say that this new color palate makes the car much more desirable. If I was in the market for a Golf R, I would absolutely spring for the Spektrum colors. Volkswagen will soon be updating their online builder tool for buyers to configure their own car. This is exciting to say the least and I hope more manufacturers stray from this whole monochrome plus red and blue palate scheme they’ve stuck to for so long.

MOTORCULT EPISODE 38 IS LIVE

On this Episode of the MotorCult podcast we talk about small and troublesome cars, including the future of Brexit, Berger’s turbocharged E30 Wagon.

On this Episode of the MotorCult podcast we talk about small and troublesome cars, including the future of Brexit, Berger’s turbocharged E30 Wagon.

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Photo Credit: Volkswagen Group

In news we talk about a tourist in Dubai who racked up $47,000 in speeding tickets in a single evening with his rented Lamborghini. Berger notes how terrible AWD turbo BMW water pumps are to service. Ryan notes how fantastic and perfect the new Suzuki Jimny is as well. We also bring up just how terrible Fastest Car on Netflix is, just in case you forgot.

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We note our favorite car designers of all time and why. These are the heroes that make the most iconic shapes of cars and make these cars just how special they are.

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For the World Cup of Cars we have two matches on this episode. Match 1 is Serbia’s Yugo GVX moving on to take on Sweden’s entire Koenigsegg brand. The second match is much more difficult because Japan is battling England with 60’s GT cars. The Toyota 2000GT battles the Aston Martin DB4, both Bond cars, both with beautiful straight 6 engines but only one will leave the victor.

To listen to MotorCult Episode 38 click the link below

MotorCult Episode 38

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