AFAIK Teflon can run pretty tight dry.
That Eaton model is a Roots, and simply moves air into the manifold. If the engine's normally aspirated intake volume (CFM) is smaller than the blower discharge volume it develops compression in the manifold. If the blower volume is less than the engine's, there will be intake vacuum and no boost at all.
How to tell: the left and right rotors are identical, and have continuous cross-section along the entire length.

The more complex Sprintex, Autorotor, Kennebell, IHI for Mazda, PSI, Whipple, &c. have asymmetrical rotors with different numbers of lobes (3 & 5, etc.) which change cross sectional area as they approach the discharge port.






More information on my site here (look for "twin screw"): http://victorylibrary.com/mopar/blower/blower-choices3.htm