One of the oddest episodes in Porsche history is the brief but meteoric career of the Type 645 Spyder, which was in public view in Germany for less than four months, from its first appearance to its last in the autumn of 1956. Its design, which dated to more than a year earlier, had been prepared as a successor to the Type 550 that would be lighter, more aerodynamic and superior in roadholding.
Porsche pitched its 550 Spyder into Europe’s most competitive sports car racing class. France was in the 1500cc category with its Gordini, Britain with Cooper and Lotus, East Germany with its six-cylinder EMWs, Italy with both Maserati and OSCA and Germany itself with fuel-injected Borgwards. Although the 550 was off to a good start with the Fuhrmann engine’s 1954 introduction, its chassis concept dated in some respects to Walter Glöckler’s racers as far back as 1950.
Egon Forstner decided to address this shortcoming. An Austrian who had joined the Porsche cadre in Gmünd in the 1940s, Forstner was a versatile engineer with patents in brake design, cooling systems, valve gear and tractor design, among others. Moving to Stuttgart, he took over from long-serving Josef Mickl as head of the calculation department. It consisted of his assistant, Ernst Henkel, and, from 1956, newcomer Hans Mezger.
The D-Train
‘The calculation department office was above the experimental department,’ recalled Mezger, ‘where everything was in one big area. We were on the third floor above the second floor office known as the D-Zug, or D-Train, because it had side windows like those on a train, looking out on the experimental area below.
‘In the D-Zug office were about eight engineers in total, with the chassis people on the left and the engine designers on the right.’
In the latter part of 1954, Forstner started work on the design of a new body and chassis to carry the Type 547 four-cam engine. Counting on their enthusiasm for racecars, he appealed to other Porsche staff for help with the project, given the Type 645 designation. Two who signed up were engineer, Ernst Fuhrmann, and body designer, Heinrich Klie.
Fuhrmann’s involvement could
