I've got away with turning the barrels on 160/175 and 180 pumps, but I wouldn't even bother with trying it on a 215. I turn them on the smaller pumps because it gives it some extra power. I've never done it on a 215 because my understanding is that turning the barrels is like your increasing rack travel, and too much rack travel on a 215 can hurt you power wise. My 215 is set up with 4kgsk, 191 dv's, 2095 rack plug, #6 plate, and .093 holders. It puts out enough fuel to be right around the 700hp mark on fuel only.