The 1939
Tripoli Grand Prix was turned into a
Voiturette race for smaller, 1500cc supercharged cars, like the factory
Alfa Romeo 158/159 Alfetta and
Maserati 4CL and 4CLT. Mercedes, believing that these rules might get adopted for GP racing, decided to invest in a new, smaller model, the V8-powered
Mercedes-Benz W165, which took a double victory in the race. Engineers of
Auto Union racing cars had witnessed Mercedes testing a "Tripoli car" at the old
Hockenheimring in April 1939, which inspired them to develop a similar project. The Auto Union Typ E was a Porsche-designed, never completed 1,482 cc (53.0 x 56.0 mm) flat-12, 2-stage Roots supercharged racer developed in 1939 and 1940. It was projected to deliver well over at 9,000 rpm. In 1946, the Voiturette rules were promoted to
Grand Prix motor racing rules, later called Formula One. The Auto Union concept provided the basis of the Cisitalia 360 car which was built in Italy by Cisitalia personnel with help from former Porsche employee
Robert Eberan von Eberhorst around a
mid mounted supercharged 1,492 cc (56.0 x 50.5 mm)
flat 12 engine giving a conservative at 8,500 rpm and a top speed of . A fully enclosed streamlined body for fast circuits was planned giving over . Later bench tests showed about at 10,500 rpm. The chassis was of
chromoly tubing and featured on/off four-wheel-drive with a
sequential gear-shift and a rear-mounted
transaxle, also sending power through a
driveshaft to a front
differential. Suspension was independent with Porsche type
trailing arms in front and parallel acting arms in the rear. Porsche's experience with the pre-war
Auto Union Grand Prix cars showed through in the layout and design of the Cisitalia to the extent that it has been referred to as the "Auto Union Type E". ==Legacy==