Question about loaded RPM

[Fluid]

Using math to predict top speed fails if the boat is not running efficiently. If it is hopping even a little that can slow things down a lot. Cell quality counts too, all the energy in a boat is in the cells, not the motor. Short wires, good connectors, perfectly aligned driveline, all count a lot at high rpm.

The v937/3 has driven riggers the size of the UL-1 to over 90 mph with round cells, but as Chris said the draggy UL-1 may meed more blade area. Try the v940/3 or even the v942/3, but you are probably pretty close to the hull's top speed for the design right now. Not every boat can go 100 mph no matter how much power you put in it.

Plenty of SAW records have been set with the v900/3 props, I've set a lot myself. The number of prop blades doesn't matter, what matters is how the particular prop pushes the hydro. You need a minimum pitch and blade area to get a bot/motor/cell combo to record speeds. Both 2 and 3 bladed props are in the record books.


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[martin]

I just find it interesting to see how close you can get with whatever calcs you use to the given speeds recorded weather it be gps or more accurate speed traps. Its just a bit of fun. Martin.

[jamie]

Hey thanks everyone for all your input and experience and Wayne i will be down at any hour to see your new cat run
Martin your right its great fun, these things get you hooked and with my lack of experience on this stuff every time i run the boat i find that i learn so much ... mostly 3 steps back and one forward LOL but thats what makes it enjoyable to me.

[martin]

I have found out of all the various forms of model boating fe seems to be the most addictive. I think its also gaining more interest than most other forms of model boating looking at the interest on forums like OSE + others of course. Martin.