You could try with rotators, see large spinner for lua part, I'm not sure if it would be any faster though as I have had bit of trouble having serious torque out from one, but maybe if using enough small diameter it would work better.
The locomotive this is based on produces 4,400 peak Horsepower. Maybe something to look into? Don't mean to be pushy or anything but 1,400 less horsepower makes a big difference EDIT: My bad, didn't think to look up the running number first
Wouldn't it be more realistic to use a direct drive electric motor? It'd probably be better than trying to couple a diesel to the wheels with a CVT, and give you a way better torque curve.
Well then. I was not expecting this. This is certainly a mod that I will download, after it's available... All I can say is good work, and keep it up.
Well the real name... (or classification) of this locomotive is the GM EMD SD40-2... although the numbers are from the snoot nose fleet... it is a different thousands series.