[Megahurtz]

Your thoughts about COT pulling SOI back to where the exhaust valve is still open are exactly what got me thinking about the theory that it would actually cool the exhaust valve down and even the cats. The effect of the fuel or especially ethanol evaporating on the way past the hot exhaust valve and cats would have a cooling effect.

I have nothing to support this as its more of a theory but I'm sure GM Engineers and some engine builders likely know. But there is really no need for COT it if you're running ethanol and high flow cats. Then it becomes that you would be backing up SOI to support a longer spray window before it sprays too far into the combustion stroke. But if you have the fuel system and don't need to cool the cats or exhaust valves, and are not spraying too far into the compression stroke, then why waste fuel out of the exhaust valve by backing SOI up to 380+? Would make more sense to start injecting close to TDC.