Re: Supercharger newbie - air flow, what's the path?
If you had even flow into a plenum then a 65 mm throttle body would be enough for about 7500 rpm. Problem is a 90 degree V6 does not have even flow, it is somewhat erratic.
That said, with boost you can make the plenum pressure anything you want provided you don't go sonic (choked flow).
It is pretty easy to tell if you need "more" for an NA engine and that is to just monitor the manifold vacuum (available as a data point in Torque, can even map to MAF reading). As long as it stays near zero you are fine but if the vacuum starts rising as you near reline under load then something is restricting flow & could be anything upstream of the measuring point, not just the throttle body.