can anyone give me the formula for prop slippage ??

RPM divided by gear ratio x pitch divided by 1056 = theoretical speed

Actual speed divided by Theoretical speed = propeller efficeincy %

100% - propeller efficency % = % slip

OR go here

http://www.go-fast.com/Prop_Slip_Calculator.htm

Julie

thank you matt and julie for your quick responce!! according to that formula my props have a 6% slip factor and my spare props have a 10 % slip factor , is this a good % of slippage??

10% is very good, 6%, theres something wring with your numbers

Keep in mind that the end result, of slip % will only be as accurate, as the numbers we use in the formula. So if any of your numbers are inaccurate then the slip% is not accurate. Hope this helps.

Julie