Turbo-Compounding and Control of Air Flow
The SuperTurbo™ also provides efficiency benefits to the engine, both directly and through enabling effects. During operation at higher engine power levels, the turbine of the SuperTurbo captures more energy from the exhaust than is needed to drive the compressor to provide boost pressure to the engine and operates in turbo-compound mode. This extra turbine power is transferred through the SuperTurbo to the engine crankshaft, providing direct power and efficiency benefits to the engine. Depending on engine duty cycles, the efficiency enabling effects can be even greater. As turbo lag is not an issue, the turbine can be higher inertia than normal, enabling higher efficiency turbine designs through larger diameter and full back wall turbines.
The SuperTurbo provides direct control of air flow to the engine, providing greater flexibility to design the engine itself for optimal efficiency through engine downspeeding and alternative combustion cycles that would create excessive turbo lag in a normal turbocharger. During transient engine operation, the SuperTurbo’s ability to quickly provide boost to the engine not only increases performance, but also allows for the fuel injected into the cylinders to be used to produce engine power more efficiently.
With a conventional turbocharger, diesel engines will over-fuel, and a portion of the fuel is used only to provide exhaust heat to power the turbocharger turbine. With the SuperTurbo, this extra fueling is not wasted on exhaust heat, but is used for in-cylinder power with the additional air flow provided.