I love the fact that the 2GR-FSE has both port and direct injection tech, but what I want to know is how it works (generally). Does it switch after a specific RPM, load on the vehicle, or something else?

For example, Honda’s VTEC “kicks in” after a specific RPM.

Thanks in advance.

 

It's actually cuter than that -- it doesn't use one injection system or the other, it often uses both at the same time. In general, a combination of engine load and RPM are the inputs to a "map" that determines how much fuel to inject from each system, and it's a gradual adjustment as those change. However at high load or high RPM it does go all the way to 100% direct injection as that allows maximum power to be developed.

It also behaves differently when the engine is cold, altering the timing of both injection systems to produce a stratified charge (richer mixture near the spark plug) so that the ignition timing can be retarded further. This makes the exhaust hotter so as to get the catalyst going sooner.

It's a pretty complicated setup and the description of it is in several different documents.

 

Here's what I've been able to find, the design philosophy behind the engine is very interesting.

I have a couple other ones talking to a comparison between the fan injector and the swirl injector as well as whitepapers on previous engines which led up to the 2 and 3GR if you're further interested.

The 2GR one I've included talks to how they developed the dual injector strategy in general... the 3GR was a slight mod on top of that work.