Saturday 4th August 1956
Wilhelm Herz rode the NSU Delphin III streamliner motorcycle to 211.4 miles per hour (340.2 km/h) at Bonneville Speedway in Utah, to break 200 mph (320 km/h) for the first time. Its fairing, designed in a wind tunnel at University of Stuttgart (then Stuttgart Technical College), gave it a drag coefficient of 0.19. The same engine powered Herz to a 1951 world speed record, with a less efficient frame/fairing, the Delphin I. The engine used an unusual rotary supercharger related to NSU’s eventual development of the Wankel engine. In the supercharger, both a trochoidal inner rotor and epitrochoidal outer rotor spun around a stationary shaft.