This unloads the motor and lets it rev faster, without losing pitch. The 215 has more pitch than the X440. 2.5 vs. 2.20. I did this twice and got great results. I compared the modded prop to a stock 215 and a stock X440. Always rebalance and resharpen after mods.
Speed is way up, pulls hard out of the corners, higher revs on the straights.
You may need to change your setup up or down on the transom for best results. As always I am open to comments on this article . Different hulls, motors, setup, will vary outcome. I am planning on starting an interview soon with Jerry from Seaducer Boats . I ran my Firefighter prototype 3 with my old OS RZM and it went great.