Rookie

iTrader: (4)

What are considered reasonable slip #'s. between 10-20% or 5-10%.
I'm at 13 and wondered how much more I reasonably could expect with a little more prop work.

jdnca1

Mine run right at 13% on twin engine cat. Bravo's.

Cord

iTrader: (2)

What kind of boat? Drives?

WETTE VETTE

So far my single engine cat runs about 18.5%. This is turning very high RPM's, and I do not know what effects that has on things. With a larger prop and less RPM the slip was in the 17% range, but the boat was 2 MPH slower. I ordered a prop that should get me somewhere in the middle and hopefully that will be the fastest and most efficient. Bravo 1 props seem to run between 12 and 20 normally and Hydro's are in the 8 to 12 range. This is generally due to the way these mfg's rate their pitch. For example a 30 Bravo will run very similar RPM's to a 28.5 Hydro. If the speeds are the same the Hydro will appear more efficient, but it is really apples and oranges. I normally look at the slip factors, but the lowest slippage prop is not necessarily going to be the best or fastest prop. Just my .02.

Craig

Rookie

iTrader: (4)

Scarab Panther TRS Quicksilver 25's

Rookie

iTrader: (4)

The reason I ask the question is last year I finally got it on the GPS and it would run 74 consistently but ALL the cupping in the props was washed out. I could not get on plane in any water over 2' they would just cavitate. I took them to the local prop shop and they added cupping. Now the boat comes out of the whole like a raped ape, planes fully at 25 mph with no tabs, and ran all day in 4' waves with no problems. The overall performance is great just the top speed is only 68.7. I still need to take back so they can finish the thinning of the blades and polishing to get me back my 100 rpm's, but I don't think that'll get me my 5 mph. I like the overall performance of the boat with their work, and it was only $100 per prop to add cupping and thinning of the blades.

I tried Hydro 25's and lost 7mph to much stern lift.