Basic composite upper intake manifolds的用法和样例：
- The upper intake connectors are the long aluminum tube looking things that are between the throttle body and the intake manifold.
- Remove intake manifold, yoke retainer and aligning yokes.
- Direct gasoline injection and hydrogen intake manifold supply.
- When there is vacuum in the intake manifold, the vacuum holds the diaphragm up.
- The main difference is how they move air to the intake manifold of the engine.