Understanding the Theory behind the flapper

[Extent]

So the flapper serves to increase air velocity by constricting the intake.  It's vacuum actuated so it's position is dependent on throttle position.  high load = low vacuum = max constriction ( default flapper location)?

The V setup doesn't take RPM into consideration, is the problem completely independent of RPM or would a 2D allow finer (more useful) control over flapper position?

[supervision]

 The type of vac, called, high vac, is like that. It is found below the throttle plate. Their is another vac, called , ported vac, that happens above the throttle, and it is highest at engine speed open throttle, that is how it can do the flap at the right time.  My flapper linkage, fell apart, right when I was going to Ron's get together, last week.  I pulled out the whole throat assy, and ran it that way!  Hauls ass!  Hd to mess with the accel pump alittle, I think it gained top speed, try it! 

[QBS]

Excellent!!  A brand new can of worms.