Though they were highly successful during the Age of Titans (1934-39) era with 24 Grand Prix victories to their credit, the Auto Union racers designed by Dr. Ferdinand Porsche were not the first to use a mid-engined layout. The Benz RH (Rennwagen Heckmotor) designed, constructed, and raced by Mannheim's Benz & Cie. beginning in 1922 (four years before their merger with Mercedes was completed) owns that honor. Four RH cars were built and two scored respectable finishes at their debut in the 1923 Monza Grand Prix.
Since Porsche was employed by Daimler from 1923 through 1929, he was well aware of the RH design's merits. In addition, two Benz RH drivers graduated to key roles at Auto Union. Adolf Rosenberger served as Porsche's financial advisor while he was designing the Auto Union's supercharged V-16 engine as a speculative venture. Willy Walb was the team's manager for the 1934 and part of the 1935 racing seasons.
To facilitate locating the engine as closely as possible to the rear wheels, Porsche implemented an original transaxle layout with the differential located ahead of the five-speed transmission. While that arrangement became common race car practice by the 1960s, it was a bold innovation in 1934.
Auto Union development engineer (beginning in 1938, chief engineer) Robert Eberhan von Eberhorst implemented what was probably the first on-board test data recorder. Designed during the mid-1930s in collaboration with Kienzle, a German instrument maker, this equipment logged speed plus shifting and braking points versus time. Lacking an engineer capable of piloting the racers at speed or a driver capable of providing technical feedback, von Eberhorst used his data recorder to gain performance insights during practice sessions.
Speedy pit stops became a priority during the Age of Titans because of the high fuel consumption and rapid tire wear experienced in this period. While a normal pit stop required 32 to 38 seconds, the Auto Union team changed two tires and dumped in 65 gallons of fuel in a record 26 seconds at the 1937 Eifelrennen race held at the Nurburgring. For some non-championship races, where extra weight was allowed, Auto Unions were equipped with the sport's first on-board pneumatic-jacking systems.
During a 1935 Nurburgring test session, a 26-year-old Ferry Porsche (Ferdinand's son and colleague) suggested using a limited-slip differential to cure the wheel-spin observed when the lusty Auto Unions accelerated hard out of tight turns. (Between 1800 and 3800 rpm, the Auto Union C-Type V-16 produced 600 lb-ft of torque. At certain races, such as Monaco, one gear was sufficient for the entire course.) Following his son's suggestion, Porsche asked ZF to supply a limited-slip device which proved quite beneficial in both testing and racing. Mercedes-Benz didn't catch on to Auto Union's strategic advantage until the following season. ...next page >>