Dieselpunks.org | March 22, 2013
Another page of the Mercedes-Benz racecar saga: the W154:
Shortly after the first races were held organizers created rules and regulations to create a somewhat level playing field and to keep things relatively safe. In that light the rules setup for Grand Prix racing from 1934 to 1936 made little sense. The main element was a maximum weight of 750 kg, leaving the rest to the imagination of the very talented designers. Not surprisingly this lead to hugely powerful engines bolted on flimsy frames; very unsafe by any measure. To add insult to injury the manufacturers could not agree on new regulations for 1937 so the madness continued for another season. Mercedes-Benz dominated that year with the W125, which featured a 592 bhp engine and little to no protection in case of an accident. Some sanity finally returned in 1938 when a minimum weight linked to a maximum displacement (3 litre supercharged or 4.5 litre Naturally Aspirated) was agreed upon.
A quick calculation in the Mercedes-Benz design office revealed that a supercharged engine would be most competitive. In many ways the new for 1938 W154 was a development of the W125, which was originally developed with the new regulations in mind.
The unusually stiff nickel-chrome molybdenum tubular ladder frame was virtually carried over. The biggest difference was the shorter wheelbase of the new car made possible by the use of a smaller engine. What also remained was the ground-breaking DeDion rear suspension. It combined the benefits of independent suspension without the dangerous side effects of the swing axles used by most competitors. Up front the W154 was suspended by double wishbones, which longitudinal torsion bars. Although the maximum weight was discarded, weight saving was still a top priority, so most chassis parts were drilled to add lightness.