I am currently upgrading my turbo vee 2 to a speed 600 race motor and a esc to handle it. My question is what size prop would be a good starting point? Right now it has a 32mm with 1.6 pitch and a 550 motor (27 turn stock) and I'm worried the faster motor will cause cavitation with this prop. I have also got a new 4mm drive shaft so finding a prop is no longer a problem.

36mm carbon 3 blade would be my choice.

A 3 blade? Correct me if I'm wrong but won't a 3 blade slow it down?

more torque, less high end

That's what I thought but I want more top speed so wouldn't it be better with a 2 blade?

a 3 blade slows down the rpms but does not slow down your speed because it always has more prop in the water pushing it.

Okay I get ya now. Sorry, us noobies can be a pain. I was just reading another thread, a guy doing the same thing to the same boat and his motor was getting real hot with a slightly bigger than stock prop so I'll try the stock one first and see how it goes.

u might cavitate a lot though.

That is true, I probably will but I have changed my order so many times already with offshore electrics I'm scared to do it again (lol). All I can do is try it and see. Your idea of going to a 3 blade makes sinse. If I do have to get a new one I'll try it.

Try the stock prop, if it runs too hot, get a smaller one, if not get an X435, or X535, (both are 35mm- 535 has more pitch but may run hotter) Generally 35 mm is the biggest diameter you should run on a submerged prop. Let us know how you make out.

Thanks MikDee. I have a 36mm with the same 1.6 pitch as stock coming and also a 36mm 3 blade with 1.4 pitch. I hope one of those will do the trick. So far heat has not been a problem after I made a new pick up. Now the motor never gets over 72 degrees even after several packs running wide open.

I don't think the 3 blade will work to well, never had much luck with them, they tend to slow the boat down, but give it more power. Try it out but it sounds like the 2 blade 36mm will be fine, just watch your heat. Good Luck

By the way, that larger pickup was a good idea.

The 36mm is way to much prop after all. I was going by tower hobbies saying the stock prop is 32mm. I checked it and it's 30mm! The boat was a real slug with the 36 so I'm ordering a 31mm, 2 blade. I'll let you know how that works.

Sorry thought your boat was a surface drive, actually if you go with a more powerful motor, usually you get more rpm even with the stock prop = faster boat. If you go with a matching size carbon fiber, or metal prop, even faster, because of less flex. As you go to a bigger prop, pay close attention to heat on, batts, wiring, ESC, & motor.

ya dude i thought it was a surface drive, thats why i suggested the 3-blade. sorry bout that.

No problem guys. The new prop (30 mm carbon) should be in Friday or Saturday. That should work out being the same size but stiffer. I'll let you know how it and the new motor works.

keep us informed on how fast it goes

I run mine with a Multiplex 19T motor and a X430 (possibly 432, I'd have to look again) metal prop on 6 3300 GP cells and the motor does not get hot and runs about 3 mph faster than stock.