Supercharger types

I understand that there are certain rule restrictions on what can be run, but I am interested in Outlaw use primarily.

What types of boost differences can be seen from varying types of superchargers (traditional roots, hi-helix roots, twin-screw), and what are the typical underdrive/overdrive numbers used for each before heat becomes too big a problem? I commonly see littlefield and kobelco at the strip where I go for Outlaw Pro-Mods...why not more Whipple or PSI (twin screws) if they can perform more efficiently?

Thanks for your help guys...

 

T.C.=12?

 

THERES A COUPLE WHIPPLES AND PSI'S OUT THERE