Holset Variable Geometry Turbocharger (VGT) technology has been applied to the Project Sidewinder Cummins for maximum diesel performance potential for both racing and street applications.

Project Sidewinder uses Holset® turbocharger technology. A modified HY55 variable geometry turbocharger (VGT) was used for maximum power during Bonneville speed record runs. The variable geometry of the Holset turbo allows rapid changes in boost pressure. In simple terms, the variable geometry technology helps the turbocharger to maximize and totally control the boost pressure over the widest range of engine operating speed as possible. By using an axially sliding ring nozzle that varies the velocity of the exhaust gasses entering the turbine housing, the constant alteration in the geometry of the turbo allows for the creation of a wide range of boost while controlling turbocharger shaft speed. This virtually eliminates turbo lag and improves power, fuel economy and noise levels.

A Holset HY40 turbocharger that does not have VGT is also being evaluated for possible street use on the Sidewinder, although the VGT HY55 may provide all the flexibility that is needed for both competition and street use.