Biggus

iTrader: (1)

I have very limited experience with cats. What would be considered normal slip for a 24 Skater with twin 220 Merc out boards?

I know that 10% is pretty hard to achieve with a v- bottom.

Is 7% slip a realistic number for 30" props on a 24 Skater?

Kurt

Biggus

iTrader: (1)

Ttt

throttleup

Yes, 7% is realistic for a cat with 3b Props.

Julie

bskater18

I'm turning 6500rpm's on my 225 promax's w/34's on my 24 skater and seeing 100-102mph on gps. How much slip is That? Thanks to Joey Impressia for the set up.

Biggus

iTrader: (1)

What's your gear ratio?

bbladesprops

I'm sure bskater is turning 1.87 gears. That puts his slip at 9.75%. That is common.

7% is possible but not necessarily common or normal. The average cat will not run 7% without playing with the engine height, set back and propping. With good set up and weight distribution it can be done or in some cases even bettered.

throttleup

Actually if we were to assume 1.87 gears the slip is right at 7%. The true pitch of a 34 cleaver is more like 33 than 34. When we calculate slip we use the actual pitch of a prop, not it's stamped pitch.

Many props are not the pitch they are marked with. The problem with using the stamped pitch is when you compare the slip of a prop from one manufacturer to another you may end up with erroneous slip computations due to variations in pitch.

Matt

bbladesprops

1.87 gears were all the 225 Pro Max came with unless special ordered and then it was tough to get. You pretty much would need to get them post buying the new engine.

Matts right, stamped pitch varies from the actual measured pitch on 99% of the stock props you buy. They can be off by .15" to 1.5" and everywhere in between. If we are to start trying to to get that exact with slip% on this board, we will have to have you send in your props to scan them before we reply. Also, what has been done to the props we are discussing? Have they been worked on at one time? We have to take this into consideration too. Cup heights affect pitch. They must be measured too. With a stiff cup the Merc cleavers are just under the stamped #.

Still, if you are running 7% in a outboard catamaran, you are doing great and in the minority. You have done your homework.

SCRAPMAN1

I Would Ask Ryan Beckley I Heard He Rode In A 24 Skater Once. Maybe Twice. :d