Abstract: A composite intake manifold system for supplying intake air to an internal combustion engine includes an intake distribution chamber coupled to a throttle valve disposed upstream thereof in a direction in which the intake air flows, longer and shorter intake pipes extending from the intake distribution chamber, bypass valves disposed in the shorter intake pipes, respectively, the longer and shorter intake pipes being joined into intake passages downstream of the bypass valves in the direction of air-flow, the intake passages being adapted to be connected to respective cylinders of the internal combustion engine. The amount of the intake air to flow into the intake distribution chamber is adjusted by the throttle valve. The bypass valves are controlled so as to be selectively fully closed, partly opened, and fully opened according to operating conditions of the internal combustion engine.