Audi built the 16-cylinder super sedan it designed in the 1930s and never built

• The Auto Union designed a 16-cylinder sport sedan that never got built
• Audi, the automaker’s successor, just built it
• The Auto Union Type 52 debuted at the 2024 Goodwood Festival of Speed

In the 1930s, Audi predecessor Auto Union designed a 16-cylinder sports sedan, but never built it. Ninety years later, it will finally make its public debut at the 2024 Goodwood Festival of Speed.

The Auto Union Type 52, also known as the Schnellsportwagen, was intended to be a high-performance road car from the firm, which was formed in 1932 from the merger of Audi, DKW, Horch, and Wanderer. It originated Audi’s four-ring logo, which represented the four component brands.

Along with Mercedes-Benz, Auto Union dominated (pre-Formula 1) grand prix racing in the 1930s. The two German automakers swept the competition aside with their Silver Arrows, so named because they raced with bare metal bodywork to save weight. History shows that she success of the Silver Arrows was a propaganda coup for the Nazi regime—which came to power around the same time—but that it didn’t translate to road cars.

Things could have been different, though. The Porsche design office (Ferdinand Porsche collaborated with Auto Union before starting his own car company after World War II) began sketching the Type 33 in late 1933 with the intention of selling it to customers for long-distance road cars like the Mille Miglia, or endurance races like the 24 Hours of Le Mans. A prototype was planned, but the project was abandoned in 1935.

That deprived the world of a truly radical machine. Underneath the sedan body, the Type 52 features a mid-mounted supercharged V-16 from an Auto Union Type A race car. Displacing 4.3 liters, the engine was intended to run lower compression (in order to use regular gasoline) and less boost than the racing version, but still would have propelled the Type 52 to a top speed of 124 mph, Audi estimates.

The design specified a 5-speed transmission also taken from the race car, but that car’s transverse leaf springs and friction dampers were replaced with longitudinal torsion spring suspension and hydraulic dampers.

Audi commissioned U.K. firm Crosthwaite & Gardner, which also maintains the automaker’s historic fleet of Silver Arrow race cars, to build the modern replica. Some changes were made, including swapping in a 6.0-liter supercharged V-16 similar from the 1936 Auto Union Type C race car, and running it on a mix of 50% methanol, 40% super unleaded gasoline, and 10% toluene. That boosts output from the original 197 hp to 512 hp.

Audi also specified a longer wheelbase, which turned out to be necessary to the drivetrain and suspension. The finished car is over 16 feet long, but has space for three people (the driver sits in the middle, McLaren F1-style), two spare tires, and luggage within its streamlined form. It will be driven at Goodwood by nine-time Le Mans winner Tom Kristensen and racing veteran Hans-Joachim Stuck, whose father Hans Stuck drove Auto Union grand prix cars in the 1930s.