Transient Supercharging Capability
The SuperTurbo™ is a step forward from a traditional turbocharger, in that it has a mechanical transmission that links the turbo shaft to the engine. This enables power transfer to and from the turbo shaft that is not possible with a normal turbocharger. During transient operation, the SuperTurbo operates in supercharging mode, powering the turbo shaft to quickly provide boost. This “efficient supercharging” only draws partial power from the engine, as the turbine assists in powering the compressor as well. During the transient, higher air-fuel ratios are possible, which increases in-cylinder efficiency and reduces PM emissions.
In heavy duty diesel engines, turbo lag can be less than half the time as compared to a traditional turbocharger. This provides greater drivability to the vehicle, especially at low engine RPMs where the engine is most efficient. It also allows for downsizing of the engine while maintaining transient performance. For construction machinery, improving transient response time can also reduce cycle time, which increases productivity of the vehicle.
As many know, braking in a vehicle is as important as the ability to accelerate. Another performance benefit of the SuperTurbo is enhanced engine compression braking at low engine RPM. The SuperTurbo operates in supercharging mode to provide more air and higher boost pressures to the engine to enable more compression braking in the engine. This expands the engine RPM operating range of the compression braking, providing a greater margin of safety for large trucks on long descents.