Historically, the development of the Roots type supercharger has not been as straight forward as its inherent balance and relatively low operating temperature might suggest. High speed, tight tolerances and high noise levels have combined to present formidable engineering challenges to successful product development.
Superchargers have traditionally exhibited high noise levels due to uneven airflow at the inlet and outlet manifolds. To provide constant inlet and outlet volumes, three lobe rotors were used with a helical twist of 60°.
To further reduce noise, special outlet port shapes were designed to lengthen the backflow compression event and thereby reduce the outlet pressure fluctuations. A computer program which modeled the thermodynamic processes and air flow rates at various speeds and pressures was used to evaluate these outlet port designs which were then incorporated and tested in prototype hardware.
Engineering efforts in component durability and especially noise control have yielded a commercially acceptable supercharger.