Question: The NSU Delphin III streamliner motorcycle set the motorcycle land speed record in what year, the engine used an unusual rotary supercharger related to NSU's eventual development of the Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into rotating motion?
Sentence (from "Pressure wave supercharger"): Although it provided a useful increase in performance it was considered too expensive to be incorporated into later models.
Relevant evidence: No