Several screws of intake manifold of BMW b48 engine

The intake manifold has eight screws. Four up, four down. The function of intake manifold is to maintain driving safety. For a carburetor or throttle body gasoline injection engine, the intake manifold refers to the intake pipe behind the carburetor or throttle body and before the intake port of the cylinder head. Its function is to distribute the mixture from carburetor or throttle body to the air intake of each cylinder.