Low-emission strategies (Euro 6 in Europe and SULEV /PZEV in the USA)
Pierburg side-channel SAP
The SAP normally extracts the air from the engine air filter via a line or, alternatively, its own secondary air filter. The air is pumped to the secondary air valve.
Mechanical Turbo-Compound (Napier Nomad, Cummins-Scania, Volvo, Daimler, Iveco)
The turbocharger with the downstream power turbine and the transmission (Turbo Compound) is located on the hot side of the engine, which provides additional effective power of up to 35 kW to reduce fuel consumption.
The combination of exhaust turbocharger, Valvetronic and direct fuel injection is known as Turbo Valvetronic Direct Injection (TVDI).
With conventional wastegated turbochargers or fixed geometry turbochargers (FGT), a turbine flow area cannot be adjusted during operation.
Knocking is abnormal combustion in which the air-fuel mixture ignites prematurely due to exposure to high temperature and pressure, creating an unwanted high-frequency noise. When the compression ratio is increased, the temperature at compression top dead center (TDC) also rises, increasing the probability of knocking.