On 3 June, Mercedes-Benz will mark 80th birthday of the legendary W 25 who gave birth to the legend of the Silver Arrows. The silver-coloured body of the W 25 Grand Prix racing car gave this nickname to the racing cars from Mercedes-Benz after Manfred von Brauchitsch drove it to victory and established a new track record for the international ”Eifelrennen” race at the Nürburgring.
It was a debut in sparkling silver, and it ended with shining gold with an average speed of 122.5 km/h. However, the victory was almost outshone by the sensational fact that the new Mercedes-Benz racing car took to the track with its aluminium body in shining silver rather than with the classic paint finish in racing white. According to the legend, the metallic silver skin was only exposed during the night before the race, by grinding off the white paint to bring the starting weight of the W 25 down to the limit prescribed by the race rules.
The new W 25 cars weighed just one kilogram too much to meet the conditions for the 750-kilogram formula. During the evening before the race, racing manager Alfred Neubauer had a brainwave: the white paintwork had to be removed, which would produce the necessary weight saving. In his book of reminiscences ”Men, Women and Engines”, Neubauer described the nighttime scene in the pits: ”Throughout that long night, the mechanics scrubbed the beautiful white paintwork from our Silver Arrows. And when they were put on the scales again next morning – they weighed precisely 750 kilos.”
The in-line eight-cylinder engine originally had a displacement of 3.4 litres and featured the supercharging that had fully proven its worth in racing. The displacement was later increased to a maximum of 4,740 cc. Depending on the version, the engine output was 260 kW (354 hp) to 363 kW (494 hp), allowing a top speed of up to 300 km/h. The most powerful engine was M 25 C and produced an output of 363 kW (494 hp) at 5800 rpm from a displacement of 4,310 cc.
The Mercedes-Benz racing drivers in the 1934 Eifel Race
The engineers around Hans Nibel, Chief Engineer at Board level, worked under considerable time pressure to develop a new racing car. The combination of a slim body, a mechanically supercharged 3.4-litre in-line eight-cylinder engine, individual wheel suspension and a transmission mounted directly on the rear axle, all added up to make the car an absolute winner. Responsible for the chassis at Daimler-Benz was Max Wagner, with the duo of Albert Heess and Otto Schilling working on the engine. In the testing department headed up by Fritz Nallinger, Georg Scheerer, one of those who had been there since the very early days of the supercharged ”Kompressor” models built by the Daimler-Motoren-Gesellschaft (DMG), was responsible for putting the engines very thoroughly through their paces. Otto Weber would assemble them, while Jakob Kraus took over the fitting of the chassis.
Photos: Daimler AG