Prop change can you explain????

[nitrosteve]

I changed my 14x17ss Vengence prop for a 13.75x19 Aluminum. I gained about 3 mph, but the rpms stayed the same. I went up in pitch, gained MPH, and the RPMs stayed the same. I was able to trim the 19 up a tad more without porpoising I thought maybe this was allowing the RPMs to go up.
Why would I be able to trim up more with the 19?
Why did my RPMS stay the same?

 

[Dhadley]

Re: Prop change can you explain????

The 19 has less slip. Remember, you're comparing a used prop to a new prop. Not all props are created equal, maybe the 17 has a less technical blade design. But for whatever reason, you've successfuly reduced slip (gained efficiency) which is the whole idea behind setting up for max efficiency. What you're seeing is not unusual.