They made the Auto Union Typ 52 based on the blueprint

Street-legal Formula 1 car: The Auto Union Typ 52 was basically a 1930s Mercedes-AMG One. However, that project was never realized. Audi decided to build the car according to the original plans

Auto Union AG, founded in 1932 through the merger of Audi, DKW, Horch and Wanderer, was early involved in motorsport to make its new brand with four rings internationally known. Also in 1932, the rules were published for a new formula of 750 kg, which should apply to Grand Prix competitions from 1934 to 1936. Back in 1933, Auto Union AG commissioned the Stuttgart design bureau of Ferdinand Porsche to develop a racing car according to this 750 kg formula.

Work on the Auto Union Typ A – named “Typ 22” according to Porsche’s internal nomenclature (Typ 30 were the first prototypes of the VW Beetle) – began in March 1933, and a year later Hans Stuck set a world record at the Berlin AVUS tracks driving that car. When the brand new Auto Union and Mercedes-Benz racing cars also entered the international racing scene in 1934, the myth of the “silver arrows” was born.

Fast cars captivated the audience: powerful cars with a futuristic design, equipped with revolutionary technology. While Mercedes-Benz favored front-mounted engines, Auto Union placed the engine behind the driver for the first time – this mid-engine concept is still standard in Formula 1 today.

Each following year new speed records were set, Auto Union won numerous mountain championships, three German championships and in 1936 the European championship with the further development of the Auto Union Typ C. The rest is history.

It is little known until now that alongside the development of Grand Prix racing cars at Auto Union AG and in the design office of Ferdinand Porsche, plans for a sports sedan suitable for the streets also began. In the conceptual documents, the term “fast sports car” is used for it, under which the vehicle was probably supposed to be marketed. Due to its specific characteristics, the car represents a classic Gran Turismo by today’s standards.

Auto Union Typ 52, the later name of the project, was to be sold to customers and could be used by them in long-distance competitions, such as the Mille Miglia. Long-distance races at Spa-Francorchamps or Le Mans could be considered, for example. There were also considerations for factory participation.

Sporting dynamics and everyday usability were in the plan of the Auto Union Typ 52. At the end of 1933, the first design sketches were created in Porsche’s design bureau, which took on more concrete forms during 1934. The project included the construction of an experimental car. According to all the knowledge we have today, that car was never built. During 1935, the project was suspended, and the traces were lost in the archives of Audi and Porsche.

Until then, the development teams noted many innovative technical details based on the parallel developed Grand Prix racing car: The Auto Union Typ 52 chassis was designed as a frame with a mid-mounted engine. The power unit from the Auto Union Typ 22 is used, but the compression of the powerful 16-cylinder engine has been reduced so that the car can run on regular fuel. Also, technicians reduce the gear ratio of the Roots compressor.

The engine in the Auto Union Typ 52 should develop around 200 horsepower from a displacement of 4.4 liters at 3,650 rpm. Its maximum torque of 4,450 cmkg (436 Nm) is reached at a moderate 2,250 rpm. Although compared to Grand Prix cars the power is reduced, the calculated performance of around 200 km/h shows that the fast sports car would live up to its name.

In its day it would have been one of the most powerful vehicles licensed to drive on the street, as well as in possible sports car competitions: a real fast sports car. Basically, a 1930s Bugatti Veyron…

Based on the remaining archive documents, plans and construction drawings, Audi commissioned Crosthwaite & Gardiner to reconstruct the Auto Union Typ 52. The English restoration specialists also maintain the Silver Arrows from Audi’s historic vehicle collection and completed the “fast sports car” project after several years of construction. in 2023. All parts are “custom made” and handcrafted especially for this model.

With a length of more than five meters, the Auto Union Typ 52 is an imposing sight: The elongated silhouette clearly shows that the engineers designed the car for the best possible aerodynamics and maximum performance. Unlike its Grand Prix cousins, it is conceptually more suitable for everyday use: with a roof, headlights and a place for luggage. Space for two spare tires was also considered.

Additional comfort will have to be sacrificed for up to three passengers. In a racing style, the driver in the Auto Union Typ 52 sits in the middle, while the front passenger seats are laterally moved slightly back. When loaded with three people, 70 kilograms of luggage and 150 kilograms of liquid, the technical data shows a total weight of 1,750 kilograms, while the empty weight of the vehicle should be 1,300 kilograms.

While the power unit and transmission, together with the open 5-speed gear lever, originate from a Grand Prix racing car, the engineers choose other technical solutions for the suspension and damping: Instead of a transverse leaf spring combined with a friction shock absorber as in the Auto Union Typ 22, in the Typ 52, longitudinally placed torsion springs in combination with hydraulic shock absorbers are used on the rear axle.

The tank, which according to the plans has a capacity of 110 liters, was moved under the seat during development – in a Grand Prix racing car, a significantly larger tank is located directly behind the driver in the center of mass of the vehicle, which in the Silver Arrows enables optimal weight distribution when the tank is full and empty. Braking on the Auto Union Typ 52, as well as on the Typ 22, is achieved by means of drum brakes on all wheels, and wheels with wire spokes are provided.

Regarding the Auto Union Typ 52, the final level of development has not been preserved, i.e. there are no traces and no pictures of the completed vehicle. During the dissolution of Auto Union AG in the Russian occupation zone after World War II, not only the historic Grand Prix racing cars disappear, but also numerous documents and photographs.

Verified reports by contemporaries, which would allow conclusions about the final configuration – if it ever existed – of the planned fast sports car, also do not exist. Nevertheless, based on the existing plans, the development direction and goals that the engineers followed at the time are clearly understandable.

During the construction phase, there was a constant and intensive dialogue between Audi Tradition and the experts from Crosthwaite & Gardiner. In its course, Timo Witt, director of Audi’s historic vehicle collection, clarified numerous details; decisions in favor of one or another technical solution had to be made.

Today, after the completion of the construction project, Witt says: “Even in the 1930s – this is one conclusion from our intensive dialogue – probably the development teams would still adjust some technical detail during testing.

So, for example, we had to extend the wheelbase of the now built Auto Union Typ 52 compared to the original plans, because it was technically the only possible solution in combination with other components such as front axle suspension, power unit, steering or gearbox. On the other hand, when designing the interior, we modeled ourselves on the Auto Union Grand Prix racing cars and at the same time interpreted the colors and materials in a contemporary way.”

The documents do not contain more detailed information about the exterior paint, i.e. the color. That’s why Audi Tradition used a racing car as a base and chose Cellulose Silver (silver in a matte shade) for the color.

With the engine in the newly built Auto Union Typ 52, there are deliberate deviations from the constructor’s original plans: Audi Tradition uses the 16-cylinder Auto Union Typ C unit, which has not been downsized to allow interchangeability with the Typ 52 Grand Prix racing cars. runs on a special mixture of methanol.

Based on the available information, which Audi Tradition interpreted and realized with maximum care, the Auto Union Typ 52 is the result of the closest approach to the fast sports car Auto Union Typ 52, conceived approximately 90 years ago, which was never built.