We need more information on your set up like prop diameter, pitch, and size and weight of your boat. Changing the pitch can help. If you want a higher top end speed then up the pitch, if you want a better hole shot then lower the pitch. It is tricky though. The key is to keep the WOT rpm at factory recommended range. Check out iboats.com and you can send them your specs and what prop you have now and they can match you with the right prop to maximize your performance.