I was reminded of this rare and unusual racing car when I saw, in the hand-out about Audi Motorsport’s very enjoyable day at Shelsley Walsh, when Neil Corner ran his V12 Auto Union, the comment that these fabulous pre-war GP Auto Unions were “the forerunner of all modern F1 designs.” It is always a dicey thing to ascribe “firsts” to any one car, unless all the facts are at one’s type-writing fingers. But I would have said that where the discussion revolves round mid-engined (or more appropriately rear-engined) racing cars the “first” probably belongs to the Benz Tropfenwagen, and not to the Auto Union.
There is no particular merit in saying this, because the 1923 Benz has been recalled by others, in quite recent times. But it seems this is the right time to remember again the rear-engined GP car devised by Willy Walb for Benz, after investigation of the 1921 Rumpler rear-engined chassis. The racing Benz cars ran in the 1923 GP de Europe at Monza, driven by Walb himself, Franz Horner, and Fernando Minoia whose racing career dated back to 1904. So as fast as the Fiats and Millers, these unconventional Benz nevertheless finished 4th (Minoia, at 84.8 mph), and 5th (Horner, at 79.7 mph). after Walb’s rear-mounted, roller-bearing, twin-cam 2-litre, six-cylinder engine had given trouble that caused his retirement.
Apart from this appearance at Monza, these Benz performed well in German hill-climbs, Horner being placed 3rd, behind two blown Mercedes at Solitude in 1924, Walb winning the Konigstuhl event with a sports-version, repeating this achievement at Freiberg in 1925, when Rosenberger was fastest at Herkules, the same driver winning a five-lap sports-car race at the new Solitude circuit, setting fastest-lap. These Benz also did well at the races held to open Opel’s new test-track, Tigler’s winning at a record 79 mph, over ten laps,
So the rear-engined Benz were no flash in an experimental pan. Nor is there anything mysterious about them, even if they may have been largely forgotten. If you want chapter and verse, Karl Ludvigsen has gone into much detail about these interesting Benz cars in his great book Mercedes-Benz Racing Cars (Bond/Parkhurst, 1971); their rear-placed engines were to do with streamlining, whereas the Auto Union, and today’s F1 cars, use them to improve weight distribution as fuel is used up. Now the Benz/Mercedes amalgamation began in 1924 and was consolidated by 1926. So it can be said that it was from Mercedes-Benz (the main challenger of Auto Union in Grand Prix racing between 1934 to 1939) that the layout of the present-day rear-engined F1 cars stemmed, not from the GP Auto Union (there is, incidentally, more than a trace of Benz Tropfenwagen in the production Type 150 Mercedes-Benz of 1934), no matter what the publicity boys and girls of Audi Motorsport may tell you! — W.B.