here are some results from doing a little prop testing all speeds are GPS

4 blade hydro 24 p
upwind downwind
3500 46.8 44
4000 54.3 49
4450max61.7 450061.9

3 blade 23p quicksilver chopper
up down
3500 39.5 41
4000 47 48
4950max 61.34950 61.1

3 blade mirage plus 23p
up down
3500 41.4 41.2
4000 51.5 50.8
4925max 63.1 497563.5


this was with 3/4 tank of full 80 humid day 1 foot chop 15mph winds boat was loaded for normal day out tools cooler 2 adults.

top speed for the day was 64.3 this was with ALOT of trim and only 1/2tank of fuel

the four blade gave the boat a ride that was excellent good feedback np porpoise or chinewalk but slowest to plane good bite

the three bale chopper rode ok some blowout when planing and not much feel in the steering no porpoising this was a prop i had laying around and figured what the heck

threer blade mirage plus qickest to plane but porpoised badly chinewalked and made boat ride very bow high also had to use a lot of trim for speed with this boat.

i think i am going to see if i cant get the extra rpms out ofthe fourblade if i cant i will sell it and get a 22 p 4 blade

the most i have gotten out of the setup was 67.2 that was 1/8 tank of fuel 50 degree day 2-3 foot chop

what do these numbers figure out slip wise??

thanx for all the help Rob

Rob, if your gear ratio is 1.5 and your prop is a 23p and your rpm is 4975 and your gps speed is 63.5 your prop slip comes out to .120961

Rob, your X demension must be pretty deep. The Hydromotive is designed to slip a little coming on plane. Does your 24 Hydro have a diffuser ring on it? If it does I would cut it off. But I think best plan would be to get a 22 pitch Hydro w/NO diffusser ring. If the 22 still won't turn to 4900 or 5000 rpm then have it labbed.

The 22 will also be better planning time than that 24. I'll keep my eyes out for ya for a 22 pitch Hydro.

Eric

dockmech yes my gear ratio is a 1.5 does that mean 12% slip?

Eric, no i dont have a difuser ring i am thinking i need a 22. i am sure i have a deep x CONVINCOR 300 is going to check intoitfor me.

should i buy a 22 or just have my 24 repicthed?? is there a diameter difference in these two??

mxz800 yes your slip is 12%. if you go to hill propellers they have a chart , you give them four of your known factors and they will give you the what you are looking for.

Rob, I would prefer to get the 22 pitch rather than have the 24 worked on. Just my opinion but would probably cost the same either way. And the stock 22 will be stronger. The diameters should all be the same. 15 1/4" to 15 1/2" diameter.

Maybe an IMCO shortie is in your future!:D

Eric

I, have said it before it's a ***** to change the pitch dn on a hydromotive prop ?the trailing edge is too thick and just wont work like a stock 22 . then you can alway's lab the prop add a touch of cupping and you will have almost the best of both worlds.or we can work the mirage to a 22 pitch ,and add cupping in the pitch and rake line ,thin out the blades and that would work we'll unless you always have a boat full of people? changing the pitch on a hydromotive prop is always easier with better results going up rather than down/hope I have helped Darin