3-stage VTEC - Stage 2

Stage 2

From ~2500–5500 RPM, all of the engine's intake valves are used. The engine now operates like a normal fixed-timing 16-valve engine. This is because as RPMs rise, the volume of air flowing increases; the small intake opening that gives good efficiency at low RPMs now becomes a restriction, so opening both intake valves doubles the air flow area. Lift is still "moderate", since the engine is only running at medium speeds, and to get good AF velocity, the valves can't lift beyond a certain point. This means there are two valves running at "low lift", instead of one.