I learned quite a bit from that link!

I'm still curious though: intake air is either pushed in via Forced Induction, or sucked by the downward motion of the piston. Either case requires that the flow is simply improved. That coupled with the fact that exhaust gas pressure and temperature is so much higher than intake pressure and temp already, shouldn't the exhaust gasses flow more quickly from an identically sized valve even before the piston pushes the rest out? That being said, once again shouldn't the exhaust then be the one requiring the improved flow?