I was thinking of ways to increase flow in the engine.

I already polished the intake side of the throttle body - easy to get at. How about polishing the intake manifold - (I think that is what it is called). I'm talking about the large assembly just downstream from the throttle body. Has anyone tried that on a 1.6 or comparable? Is this possible?

The assembly looks like it has a black plastic exterior. Is it all plastic?

- W