# How much does prop diameter matter? Ankona SUV 17



## whitmanbarnes (Mar 26, 2015)

I have a 2017 Ankona SUV 17 with a 50 suzuki and am looking to find a good backup prop. 

My current is the stock stainless 3-blade, 11 3/4" x 15 and it runs well. I am looking for the same prop, but can't seem to find it for sale anywhere. The closest I can find is a 11" x 15. Is the 3/4" going to make a difference? 

I have searched the internet for how diameter will affect performance and the only answer I can find is it will increase my RPMs. My current setup will run right at 5500 rpms WOT, so I don't want to increase by too much. I am not expert on props, but have a basic understanding of how pitch and diameter correlates. Any information would be helpful.


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## Xcapnjoe (Jun 5, 2013)

Jeff at Olympic Propellers told me when you go from a 3 blade to a 4 blade you need to decrease the pitch by two. A 15 becomes a 13. Cupping will decrease your rpms by approximately 200.
You can negate that 200 rpm drop by decreasing the diameter of the prop to even out the rpm's. By that logic I ordered a 4B 10.75 13p with a little cupping.

I'm running a 3 blade PT prop now. 11.25 diameter with a 15 pitch. Clocking about the same rpm's you are at WOT. Jeff sold it to me.

My backup prop is aluminum. Stainless is heavy when every pound matters.


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## whitmanbarnes (Mar 26, 2015)

Awesome, just the information I was looking for. Thanks!


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