Manifold design advantages

The design of gas manifolds is also a matter of art. In order for each cylinder of the engine to burn equally, the manifolds of each cylinder must be as long and curved as possible. Since the engine runs on four strokes, each cylinder of the engine is pumped in pulses. As a rule of thumb, longer manifolds are suitable for low RPM operations, while shorter manifolds are suitable for high RPM operations. So some models will use variable length intake manifold, or continuous variable length intake manifold, so that the engine can play a better performance in all speed domains.