[RedDevil]

I like the suggestion of combining (increased?) EGR with water injection.
I saw heat was a limiting factor on EGR flow.

I am confused though as why it has to be a true vapor.
I feel the coarseness of the spray can be an issue, of benefit or otherwise. Deliberately using tiny droplets instead of fine spray could help as they would evaporate more slowly, like after combustion instead of during, not hindring the combustion process too much but still add to the volume of the exhaust gas. But it is just an idea and I realize how much that depends on the other parameters (like revs, pressure, fuel mixture, temperature) to work or be detrimental.

I overstep my knowledge on this, but pray the corral will be mild to me.