Synchronizer and Shift System Optimization for Improved Manual Transmission Shiftability 891998

The R30A manual transmission mounted in the new Nissan 300ZX was developed to optimize shif-tability. Numerous performance improvements were made to achieve that goal, centering particularly on the development of a new double-cone synchronizer. Several new techniques were developed to evaluate shiftability quantitatively and supplemented conventional procedures, which are primarily based on subjective evaluation methods. As a result, the R30A transmission provides shiftability optimized for use in a high-performance sports car. This paper presents the methods used in evaluating shiftability and describes the features of the R30A that contribute to improved shiftability. It also presents the results of experiments carried out to confirm the improved performance.