Mercedes-Benz T80

Mercedes-Benz T80

Production	one-off (1939)
Body style(s)	six-wheel, mid-engined, 1-seater experimental racing car
Engine(s)	3000 hp 44.5 Litre Daimler-Benz DB 603 V12
Related	Mercedes Silver Arrows Mercedes-Benz W125 Rekordwagen

The Mercedes-Benz T80 was a vehicle developed and built by Mercedes-Benz, and designed by Ferdinand Porsche. It was intended to break the world land speed record, but never made the attempt, having been over-taken 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 Hitler himself (a race car fan influenced by Stuck), 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 550 km/h (342 mph), but after George Eyston's and John Cobb's successful LSR runs of 1938-39 the target speed was raised to 600 km/h (373 mph). By late 1939, when the project was finished, the target speed was a much higher 750 km/h (465 mph). 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 proven itself ideal for record-breaking in smaller capacity classes, Britain's Goldie Gardner having exceeded 200 mph (320 km/h) there in a 1,500 cc MG.

Power

For the job of powering a record-setting craft, the massive 44.5 litre Daimler-Benz DB 603 inverted V12 was selected for the job. This was a derivative of the famous DB-601 aircraft engine which powered the Messerschmitt Bf 109 fighter in production at the time. The DB-603 fitted was just the third prototype (V3) engine of this variant and tuned up to 3,000 hp (2,200 kW), roughly twice the power of the Bf 109 or the Supermarine Spitfire. The engine ran on a special mixture of methyl alcohol (63%), benzene (16%), ethanol (12%), acetone (4.4%), nitrobenzene (2.2%), avgas (2%), and ether (0.4%) with MW (methanol-water) injection for charge cooling and as an anti-detonant.
Although this power figure sounds impressive, it's not unusual for one-off racing engines or the period, especially those used for short-duration record-breaking with esoteric fuels. The Rolls-Royce R-type, a more comparable engine than the Spitfire's Merlin, had delivered 2,350 hp (1,750 kW) on a similar fuel mixture back in 1931. Eyston's land speed record car Thunderbolt used a pair of them, and offered over 4,000 hp (3,000 kW).

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 8 meters long (27 ft), had three axles with two of them driven, weighed over 2.7 metric tons (three short tons), and produced 3000 hp (2200 kW) together with the aerodynamics of specialist Josef Mikcl to attain a projected speed of 750 km/h (465 mph). Aerodynamically, the T80 incorporated a Porsche-designed enclosed cockpit, low sloping hood, rounded fenders, and elongated tail booms. At the rear were two small wings to provide downforce and insure stability. 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 Dessau Autobahn (now part of the modern A9 Autobahn), which was 25 metres (82 ft) wide and 10-kilometre (6.2 mi) long with the median paved over. The date was set for the January 1940 "RekordWoche" (Record/Speed Week), but the outbreak of the war prevented the T80 run. In 1939, the vehicle had been unofficially nicknamed Schwarzer Vogel (Black Bird) by Hitler and was to be painted in German nationalistic colors complete with German Adler (Eagle) and Hakenkreuz (Swastika). But the event was cancelled and the T80 garaged.

War

The DB-603 aircraft engine was subsequently removed during the war while the vehicle was moved to safety and storage in Karnten, Austria. The T80 survived the war, unlike many German artifacts, 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 634 km/h (394 mph) in 1947, a speed which was 116 km/h (72 mph) slower than the 750 km/h (465 mph) projected for the T80 back in 1940. It took until 1964 for Art Arfons to hit 875 km/h (544 mph) in the turbojet-powered "Green Monster" to attain and surpass the T80's speed target. No wheel-driven speed run vehicle exceeded this speed until 2001, when Don Vesco's turbine-engined "Turbinator" attained 458.440 mph (737.788 km/h) at Bonneville.

Current status

The T80 is currently on display at the Mercedes-Benz Museum in Stuttgart-Bad Cannstatt. Many people over the decades have urged Mercedes to fully restore the T80 and test run her to see if she would have reached 750 km/h (465 mph).