Designfax weekly eMagazine

Subscribe Today!

Archives

View Archives

Partners

Manufacturing Center
Product Spotlight

Modern Applications News
Metalworking Ideas For
Today's Job Shops

Tooling and Production
Strategies for large
metalworking plants

Audi rebuilds 1930s record-breaking aero speedster

After just over three years of construction, Audi has fully recreated the Auto Union Lucca -- a record-breaking car first built in 1935. [Credit: All images courtesy of Audi]

 

 

Audi has recreated a blast from its past in the form of the extreme-aero Auto Union Lucca, the fastest road racer in the world back in 1935. Sporting a massive V-16 powerplant, the mid-engine car reached a top speed over 200 mph back then and was emblematic of the top-tier technical innovation of the four rings in the 1930s. Since the original car does not exist, the rebuild was based on historical photos and various archival documents. Audi commissioned Crosthwaite & Gardiner to recreate the Auto Union Lucca.

On Feb. 15, 1935, the car, also called a "Rennlimousinen" (German for racing sedan), set a widely acclaimed flying-start mile record on a straight section of the autostrada near Lucca, Italy, achieving a calculated average speed of 199 mph and a measured top speed of 203 mph.

Historical photo: The original record-breaking Auto Union Lucca car in the workshop of the racing department in Zwickau, Germany.

 

 

Historical photo: The Lucca car during the record runs in Italy in 1935.

 

 

Back in the 1930s, speed is far more than a mundane measurement: Grand Prix races and the constant breaking of speed records are followed and celebrated almost obsessively by the media and the public. Over the years, Germany becomes the scene of fierce competition among brands, drivers, and technologies. It's the star versus the four rings, Caracciola and von Brauchitsch versus Stuck and Rosemeyer, front engine versus mid-engine.

Auto Union AG, founded in 1932 by a merger of Audi, DKW, Horch, and Wanderer, enters its first Grand Prix season under the new 750-kg formula in 1934 with the 291-hp Auto Union Type A. That same year, it leads the way in terms of speed records: Auto Union sets three world records on March 6 and five more on October 20 -- all in a car driven by the experienced racing driver and hill-climb specialist Hans Stuck.

Daimler-Benz AG steps up its game when Rudolf Caracciola ties Stuck's record and, in late October 1934, sets several international records on the highway near Gyón, Hungary, in a specially built record-attempt car. Among other records, Caracciola reaches an average speed of 196.7 mph over a mile from a flying start. This is the speed to beat.

The race engineers and mechanics at Auto Union are already planning the next record attempts for early 1935, so they need to level up their racing car. Based on the vehicle used to set the records in October, the experts first develop a wind tunnel model.

Historical photo: Auto Union Lucca wind tunnel model in 1934.

 

 

The model undergoes various tests -- first as an open version, then with a closed cockpit for improved aerodynamics. Auto Union's racing division incorporates the findings from the wind tunnel at the Berlin-Adlershof Aeronautical Research Institute into the design of what will later become the record-breaking car -- "a first in European racing car construction," as the "Automobilrevue" noted at the time.

According to Audi, the body of the real race car is then finely sanded and coated with clear lacquer, and the spoked wheels are fitted with wheel covers. Two circular openings at the rear serve as fresh air intakes for the carburetor. The exhaust pipes point upward and are grouped into two outlets on each side.

The car is already equipped with a 16-cylinder engine from the 1935 season, and the displacement has been increased to approximately 5 liters; however, this early version of the engine, with its 338 hp, does not quite reach the power output of 370 hp achieved later in 1935. The chassis and suspension are still those of the 1934 racing car, whereas the elongated, aerodynamic silhouette, with its fin-like rear end and teardrop-shaped wheel arches, clearly stands out from its racing counterparts of the previous season. At the same time, these changes, which are primarily technical and functional, give rise to an aesthetic of speed that makes the Rennlimousine a one-of-a-kind ride.

After just a few weeks of development work, the car is finished by December 1934. It is test-driven for the first time on Berlin's Avus circuit on December 17, and at the end of January 1935, the decision is made: The record attempt will take place in Hungary -- on the very same track where Caracciola set the class record for a flying-start mile in a Mercedes the previous year.

On February 4-5, 1935, however, the weather does not cooperate with the racers' plans. The Auto Union team heads south and finally finds a suitable kilometer-long racing stretch on the Florence-Viareggio road between Pescia and Altopascio, Italy, near the city of Lucca. On February 15, 1935, after several test runs and car reconfigurations, Hans Stuck is at the wheel, and "thousands" of spectators reportedly watch the test runs. Official timekeepers are also on hand: the independent chronometrists, as they are called at the time, use state-of-the-art chronometers equipped with electrically triggered photocells.

Stuck makes a few attempts; some adjustments are made to the Rennlimousine. With the front of the radiator sealed -- the radiator grille is covered except for a small opening -- and further aerodynamic optimizations, the ambitious goal is finally achieved: Over two averaged runs, the flying-start mile record in International Class C is set at an average speed of 199 mph. Furthermore, the measuring devices record a time of just 11.01 sec for a section of the return run in "Run 3 Stuck II," which corresponds to a blistering speed of 203 mph -- making the car the "fastest road racing car in the world."

At almost the same time as the successful record attempt in Lucca, a virtually identical version of the record-breaking car is unveiled at the International Motor Show in Berlin (February 14-24).

The modified Lucca car makes its next appearance just a few months after setting the record in Italy, this time accompanied by its Berlin counterpart. The cars enter the Avus Race in Berlin but encounter some technical difficulties and are not winners.

The 1930s are a prime example of just how fast-paced motorsport is and how many ups and downs, successes, and dramatic moments it has to offer: the Lucca car sets a speed record in Italy in mid-February 1935, but by the end of May neither of the two Rennlimousinen make it to the finish line of the Avus race in Berlin. Both cars are eventually lost to history during WWII.

Audi had the Auto Union Lucca recreated by Crosthwaite & Gardiner based on historical photos and various other documents from its archives. After spending just over three years on its construction, the British restoration specialists completed the project in early 2026.

All components on the new car have been handcrafted especially for this model. In addition to the technical implementation, the production of the streamlined bodywork, such as the cockpit canopy and the tapered tail, proved to be particularly labor intensive. Eventually, the hard work paid off. At the end of April 2026, a drag coefficient of 0.43 was measured for the recreated record-breaking car in the Audi wind tunnel.

Project manager for the construction of the Auto Union Lucca was Timo Witt. Audi says he has been in charge of the historic vehicle collection at Audi Tradition since 2015 and previously spent more than 10 years as a motorsport engineer.

"I'm impressed by the agility and speed with which they responded to the competition back then -- in the technical realm, in vehicle development, and in organizational matters," said Witt. "When the weather takes a turn, the whole team moves on without hesitation. Without this high degree of flexibility or the ability to adapt to new situations at lightning speed, the record-breaking drive in Lucca would not have been possible."

"Of course, we recreated the car as authentically as possible, but at the same time, issues such as the car's durability and maximizing efficiency in the project's implementation were also important to us," said Witt. Two examples are:

• Audi Tradition has fitted the new Lucca with the 16-cylinder engine from the Auto Union Type C, because its 6-liter engine is visually indistinguishable from a 5-liter engine, making the engines interchangeable within the Silver Arrow family.
• The Auto Union Lucca also features several modifications that were implemented for the Avus race in Berlin in May 1935, such as the ventilation system.

"We made these changes to the Auto Union Lucca because, otherwise, the vehicle would have been subjected to excessive thermal stress during our upcoming demonstration runs," said Witt. With minor modifications to the radiator or the body panels, the Auto Union Lucca can be converted into the Avus car.

Whether in the Lucca or Avus configuration, the Auto Union Lucca embodies the deeply emotional fusion of maximum performance and elegant lines. The one-off Auto Union Lucca will make its first public appearance in motion at the Festival of Speed from July 9 to 12 at Goodwood in England. The power output for the new vehicle has been upped to 513 hp (382 kW) at 4,500 rpm. Its fuel mix is: 50% methanol, 40% premium unleaded, and 10% toluene. It is 15 ft long with a curb weight of 2,116 lb. The body is primarily made of hand-beaten aluminum.

Source: Audi

Published May 2026

Rate this article