I'm finishing studying EFI systems, which set me thinking about induction more generally.

We inject fuel from a high-pressure common rail for many good reasons. We're capable of making stratified burn within a cylinder, provided we have full control of the throttle butterfly. We sometimes use exhaust gas recirculation to retard combustion and lower cylinder temperature.

Given those scenarios, why don't we add a common rail of high-pressure atmospheric air, and use injectors to introduce air, and exhaust when required, in a similar way to fuel?

Surely this would give me an engine that can respond quicker because there's no lag in the inlet airflow, have fewer mechanical parts and potentially reduce emissions by allowing me to control the oxygen content at the catalyst more easily?