The Mercedes-Benz T80 was a six-wheeled vehicle built by Mercedes-Benz, developed and designed by Ferdinand Porsche. It was intended to break the world land speed record, but never made the attempt, the project having been overtaken by the outbreak of World War II.
Background
World-renowned German auto racer Hans Stuck's pet project was to take the world land speed record and he convinced Mercedes-Benz to build a special racing car for the attempt. Officially sanctioned by Adolf Hitler, the project was started in 1937, while the Nazi Third Reich was at the height of its powers. Automotive designer Dr Ferdinand Porsche first targeted a speed of, but after George Eyston's and John Cobb's successful LSR runs of 1938 and 1939 the target speed was raised to. By late 1939, when the project was finished, the target speed was a much higher. This would also be the first attempt at the absolute land speed record on German soil, Hitler envisioned the T80 as another propaganda triumph of German technological superiority to be witnessed by all the world, courtesy of German television. The same Autobahn course had already been proven ideal for record-breaking in smaller capacity classes, Britain's Goldie Gardner having exceeded there in a 1,500 cc MG.
Power
The massive 44.5 litre Daimler-Benz DB 603 inverted V12 was selected to power the record-setting car. The engine was an increased displacement derivative of the famous DB-601aircraft engine that powered the Messerschmitt Bf 109 fighter in production at the time, with the DB 603 ending up as the largest displacement inverted V12 aviation engine in production for Germany during the World War II years. The DB-603 fitted was just the third prototype engine of this variant and tuned up to, roughly twice the power of the Bf 109 or the Supermarine Spitfire. The engine ran on a special mixture of methyl alcohol, benzene, ethanol, acetone, nitrobenzene, avgas, and ether with MW injection for charge cooling and as an anti-detonant.
Construction
The difficulty of the challenge was met with money and engineering genius. By 1939, the T80 was fully completed at a cost of RM 600,000. The car was over long, had three axles with two of them driven, weighed over 2.7 metric tons, and produced together with the aerodynamics of specialist Josef Mickl to attain a projected speed of. Aerodynamically, the T80 incorporated a Porsche-designed enclosed cockpit, low sloping bonnet, rounded wings, and elongated tail booms. Midway down the body were two small wings to provide downforce and ensure stability - these wings were inspired by the wings of Opel's famous rocket cars from 1928. The heavily streamlined twin-tailed body achieved a drag coefficient of 0.18, an astonishingly low figure for any vehicle.
Projections for the 1940 land speed record attempt
As ambitiously planned, Hans Stuck would have driven the T80 over a special stretch of the Reichsautobahn Berlin — Halle/Leipzig, which passed south of Dessau between the modern A9 freeway's exits 11 and 12, which was wide and almost long with the median paved over as the Dessauer Rennstrecke. The date was set for the January 1940 "RekordWoche", but the war begun on September 1, 1939 prevented the T80 run. In 1939, the vehicle had been unofficially nicknamed Schwarzer Vogel by Hitler and was to be painted in German nationalistic colours, complete with German Adler and Hakenkreuz, but the event was cancelled and the T80 garaged.
The DB 603 aircraft engine was subsequently removed during the war while the vehicle was moved to safety and storage in Kärnten, Austria. The T80 survived the war and was eventually moved into the Mercedes-Benz Museum in Stuttgart for permanent display. After the war, John Cobb drove the Railton Mobil Special to a land speed record of in 1947, a speed which was slower than the projected for the T80 in 1940. It took until 1964 for Art Arfons to hit in the turbojet-powered "Green Monster" to attain and surpass the T80's speed target, purely on the jet thrust for the Arfons vehicle. The wheel-driven record of was set by the four-Chrysler Hemi-engined Goldenrod car in 1965; this is still the piston-engined land speed record for non-supercharged, wheel-driven cars. Since the DB 603 engine possessed a mechanically-driven centrifugal supercharger in its normal form, the T80 would have been classed differently from the Goldenrod. No wheel-driven land speed record vehicle exceeded the T80's maximum design velocity until 2001, when Don Vesco's turboshaft-powered "Turbinator" attained at Bonneville.
Current status
The T80 is currently on display at the Mercedes-Benz Museum in Stuttgart-Bad Cannstatt.
