Method for Operating A Turbocharged Internal Combustion Engine with Turbolag Compensation

A method for operating a turbocharged internal combustion engine, the method comprising the steps of:

• providing an internal combustion engine having:
• an engine block with one or more combustion chambers, each chamber having an intake opening and inlet valve and an exhaust opening and outlet valve;
• an inlet manifold connecting a central combustion air inlet duct to the intake openings and inlet valves;
• an outlet manifold connecting the exhaust openings and outlet valves to a central exhaust gas outlet duct;
• a turbocharger having a turbine portion and a compressor portion, the turbine portion being positioned inside the central exhaust gas outlet duct, and the compressor portion being positioned inside the central combustion air inlet duct;
• and
• a secondary air injection system for injecting pressurized secondary air into the engine,
• operating the engine by feeding combustion air and/or fuel into the one or more combustion chambers via their intake openings and inlet valves, combusting the air and fuel and having a flow of exhaust gases flow out via the exhaust openings and outlet valves, with the flow of exhaust gases driving the turbine portion which in turn drives the compressor portion for compressing combustion air prior to being fed into the one or more combustion chambers;
• activating the secondary air injection system for injecting pressurized secondary air into the engine during an accelerating operation of the engine, and wherein during said accelerating operation of the engine one or more loads of pressurized secondary air are injected into the outlet manifold, with the secondary air being injected at a temperature which is lower than the temperature of the exhaust gases in the outlet manifold, and with the secondary air being injected at a pressure which is higher than the pressure of the exhaust gases in the outlet manifold, such that the injected secondary air expands before reaching the turbine portion.