Prop Slip

[jango]

Currently using a 11 x 15, 3 blade, turning 6500 rpm w. 7% slip. Speed - 85.9 mph(GPS). My question is, will slip decrease and how much, if Dia is increased to 12 with same pitch (15) and rpm remains at 6500. I realize current slip is low and may be optimum.
Thanks, Jango

[Mark75H]

Props and set ups vary so much that you can never know. You have to try it to know