There are quite a few variables when recommending a prop for an application. I prefer to speak with the owner and make sure I get it right. So far, I have only one returned prop for the wrong performance application out of over 500 sold last year. Sure, it takes 5-10 minutes. So what? Most people value their weekends too much to waste time on the wrong prop even for one weekend.
Here are the basics:
Lower pitch increase rpm - higher pitch decreases rpms. Higher rpms within reason allow more torque at wakeboarding speeds.
A larger diameter increases the amount of water "grabbed" each revolution. Larger diameters take more torque to turn.
Cup increases pitch at higher rpm while preserving hole shot. About a .125 cup is the pratical limit. Most of the time a .090 or .105 is about the max for wakeboarding applications. Some applications will do better with little cup.
A prop can only do so much. I have a lot of requests for miracles in boats with too little motor for the ballast the owner puts in. The prop can help, but it won't cure an underpowered boat for the ballast application. For example, don't expect a 22 foot boat with 5,000 lbs of ballast and load to perform well with a 315 hp motor. If you have a 22 foot boat and want to run that much, you really want at least 370 hp and hopefully a big block. Look at the torque figures from motor to motor. You want to match the engines torque curve to your prop. It is not rocket science, but experience does help.
Questions?
rider@boarditup.com or
www.boarditup.com