With more than 25 years’ experience in development, testing and application, Cummins Turbo Technologies produces world-class two-stage systems proven to meet and exceed requirements from a vast array of applications. The systems utilise various proprietary component technologies and designs to meet leading emissons requirements. For more than 25 years, Cummins Turbo Technologies has developed, tested and produced the sturdy Holset S² serial two-stage turbocharger. This turbocharger has assisted numerous high-power applications with its passive boosting technology. The newest member of the Holset two-stage family is the Holset M²™ system, providing modulation capability using any of the following variable turbine technologies; Holset Wastegate, Holset VGT™ or Holset Rotary Turbine Control (RTC) technology. A modulated two-stage system combines benefits of conventional and sequential turbochargers. The modulated two-stage system can have a high-pressure turbocharger far smaller than that of a conventional two-stage system, improving transient performance by reducing the turbocharger lag that affects both driveability and emissions.

Holset S2

Serial two-stage system, for passive boosting without active control.

Holset M²

Holset M²™ Modulated two stage system.


Product Features & Benefits

  • Enables higher engine horsepower density for engine downsizing and increased power levels
  • Efficient ultra-high boosting capability with fewer turbo limitations
  • Extended air flow range flexibility
  • Superior altitude air capabilities without exceeding limits
  • Reduced air handling controls complexity