Abstract: An internal combustion engine at least two intake valves and one exhaust valve per cylinder. The valves are actuated by an intake camshaft and an exhaust camshaft operating with variable timings. The internal combustion engine is also provided with an intake system having separate intake ducts leading to the intake valves. One control flap is provided in at least one intake duct. To optimize the operation of the internal combustion engine with regard to exhaust emissions, fuel consumption, performance, and torque, the timings of the valves and the throughputs of the intake ducts are influenced as a function of the defined characteristic map areas of a torque-rpm graph.

Abstract: An apparatus for the simulation of variable air pressures, particularly for analyzing the influence of variable air pressures on the exhaust emissions, power output, and fuel consumption of an internal combustion engine includes a canister connected to the engine by way of its intake and exhaust pipes. A vacuum pump is connected with the cannister to withdraw the contents thereof and a throttle valve is associated with a further opening in the canister for regulating the air input to the canister irrespective of the operating conditions and range of the engine. This throttle valve device is formed as a self-regulating throttle device.