I just read an article on the Renesis and the following comment was found:

"A small tube within the intake manifold provides a small, high-speed air
curtain, which enhances fuel atomization."

This is the first I have heard of this use of that tube.  I have a hose
connected to that tube which I am using to provide vacuum to my fuel
pressure regulator.

Should this tube be left open to provide that "air curtain".?

Bill B