Cfm = ((cui *rpms)) /3456) X Ve Cfm ??

[Guest tony78_280z]

In David Vizard's How to bulid horse power Vol.2 Caruretors and Intake Manifold he says, "If all other aspects are equal, a carburetor appears to the engine, to be about 15 to 20% smaller on a two plane than a single plane (manifold)."

 

If this is true, is the original forumula CFM = ((CUI *RPMS)) /3456) X VE based on a two plane or a single plane manifold?

 

 

For Dual is it (CFM x 0.8) = ((CUI *RPMS)) /3456) X VE

or is it

 

For single is it (CFM x 1.2) = ((CUI *RPMS)) /3456) X VE

 

I know it doesn't look like a big deal. The difference can end up being a few hundred two a thousand RPMs. And I'd like to get the specifics for the program I'm writing.