Intake manifold with multiple pipes

A manifold with several tubes is assembled from preformed component parts. Each tube is partly formed by wall(s) of at least one part together with a structural insert. An Independent claim is included for the following: (a) forming a manifold as above. Each tube of the manifold is assembled from upper and lower parts that fit around an insert that engages housings in the lower part. The two parts are assembled by vibration welding along the length of their weld line.