Thanks, dudes! I wouldn't have thought that EGV was important on non-turbo cars, althought it would seem the engine would still be able to move all of the exhaust gasses out of the combustion chamber prior to its next cycle.
So if I'm understanding correctly, all that matters is that the entire amount of exhaust gas is extracted from the cylinder, whereas EGV itself doesn't matter, it's just a sort of diffusion or 'sucking' force that helps to extract the EG volume, and a low enough EGV would leave excess EG trapped in the cylinder, and this is the "choke" that was mentioned? It seems like this would be a pretty significant power loss, but I've heard that any low-end torque lost due to an unrestricted (to any degree) exhaust is overcompensated for in the higher end, so if streetability isn't an issue, the widest EG exit is the optimum. Correct me if I'm wrong with anything here.