The title says it all....

Here is that great post Steven submitted a while back in the Big SV27 thread. Good Stuff.........

".....I ran the Supervee boat again today.

All tests were with gp3700 packs. The packs are last years race packs, that have lots of wear and tear on them. I ran 12 cells total. I ran middle of the road packs. Not hot dog packs that some newbies might not be able to buy. I wasn't trying for best best speeds possible, just the best all around prop. So the mph numbers with new ib4200 packs will be better.

The lake was like glass. A good day for testing.


1st run a graupner 42mm carbon prop. Hit 28mph, take off was good and had much better handling than the stock prop. But at a significant speed loss.

2nd x637 with the tabs down it was a tick over 27 and handled just as well as the 42mm carbon prop. Take off was just a bit better than the stock prop.

After the second set of laps I put the tabs back to neutral. Now all the rest of the testes were done that way.

3rd x637 with the tabs set at neutral it hit 30.8. Handling was loose but controllable. Take off is slightly better than the stock prop.

4th stock prop hit 30.2mph, take off cavitated for the first 8-12'

After the first set of tests the motor was 103 and the esc 88 degrees.

Using another set of gp3700 cells.

5th x642 by far the best take off with almost no cavitation. and a top speed of 36.1 but real loose at the end of the straight!

6th back to stock prop for a 32.3mph run. Still cavitated and just as loose as the x642 in the 5th test.

7th Back to x642 to end the testing and hit 35.8mph.

After the second set of tests the motor was 118 and the esc 99 degrees.

8th test was an older set of gp3700's with the x642. We hit 35.1mph We took a video of this run. You can tell that the boat runs way to loose. I will post the video soon. The boat ran for about 5 minutes before it flipped, ending the run. After draining the pack we figured the Calculations the current draw was about 31amps.

Steven
www.OffshoreElectrics.com

Steven
Are you going to post the Video of the supervee? So the x642 is the best prop? Grimracer said x440 he got 38 mph with duartrax 3800's?
Dan

I sharpen and balance metal boat props. PM me for more info.

I ordered a couple of props for testing... Once they come in, I'll try 'em out and post results.

Ok, sharpened, balanced and modified a Prather 215 in stainless.

The prop turned out beautiful!

It also made the boat slower. Very stable, though.

So far, the boat seems to be the fastest with the Octura x440 3 blade. I have some Prather props to try out but I'm running into an issue with the length of the prop shaft - It's too damn short and I don't have enough thread to try out the Carbon Fiber props I picked up. I'll invistigate more in the AM.

I ALMOST had the same issue with my carbon props. However there is about four threads left after installed carbon props and the prop nut. very short shaft

Ok, after a little grinding on the shaft, I was able to move the drive dog up enough to get the nut on to the point that the lock works.

Next up is a 48mm Graupner prop, followed up by a Prather 225 that I just got done with today. The Prather prop turned out sweet! Was 95% balanced after I was done removing the flash and sharpening it; took next to nothing to finish off. I wish they were all that easy.

Okay, maybe I have done it wrong all the time , balanced and sharpened an Octura 440/3 and 445 myself, and finally today received in the mail a balanced/sharpened 445 ( still waiting on the Prather 220, and set of Octuras 440/3 - one of which is cupped). The balanced and sharpened 445 came from funrcboats, only the back (facing forward when mounted) of the prop was polished. ??? Is that normal, does the front of the prop have no effect? I always polished everything and from pictures what others have the whole mounted prop looks polished.

Also received the whole set of carbon props from Offshore Electrics, hope the weather holds up, busy testing weekend, with the Annapolis Powerboatshow in town as well

The yellow (Brushless Boat) was polished/balanced from Chris Fine and the Red/White Shockwave 55 SS boat was balanced/polished from a local guy who races gasoline RC boats.

http://www.offshoreelectrics.com/prop_balance.htm

What about using 2 cell Lipos in this boat? How many cells will the ESC take? Would it be able to take 2 x 3 cell lipos? This looks like a great little boat and a fast one at that. Any comments appreciated! Thanks

Worked Prather 220 here.

Anyone know if a smaller prop at higher rpm will work here? Going to 14cells and the Prather 220 I show will be used, this is on the smaller end of the props as I see it.

-WL

Little OT. I grew up in Eugene. Didn't they have a boat pond north of the river by the Ferry street bridge and is Eugene Hobby still goin ? I just ck'd the dopp;er. Doesn't look bad there. Big time wind and rain here .. lol

i have a pretty good luck running a v937/3 you have to through the boat to start becauce it cavitates like crazy

here it is

ohh look at it !! lol
where?

No,this is normal,what this kind of finish does is it helps
'grab' the water instead of slipping against it,effectivly pushing the water out faster on the exit side,while the polished side lets it slip and be pulled by the unpolished side.

I went to a x445 sometime ago for my 14 cell usage and the boat almost jumps out of the water on takeoff.check out the supervee aeronautics video ,it was just a test of this props 'holeshot' ability on 14 cells,still need to gps,but it is probably in the 40 or close catagory.

You mentioned something I don't recall seeing being posted....throwing the boat in. I don't think alot of people realize, or at least new ones to the sport, that there's a trade off on the props. Some props will give you a hole shot but limit top speed to 35-38mph with no cavatation, and others will give alot of cavatation but give you 40mph, the later being the ones you throw in.

Maybe this is why the pros throw there boats in the water? Things that make you go "What The..."

Yes,he is pretty much righ on here, The trick is to find that prop that doesn't always require you to toss it in, and still get good speed for everyday use,and if your limited to 'only 35-38mph',that is HAULIN' for this type boat,besides there are a couple props that will give high speed and still holeshot nicely on 7 or14 cells.If I were to race this boat then I would change out the prop to give the best runtime/power combo for the rules/size of that race coarse ,which is why we experiment with them,there is no perfect prop for all situations .The size of the pond I run my boat in governs the prop usage for me,so if you bring a stock prop there and I run my 220 prather,say,and every thing else is equal,I would win the race because my prop would be Much quicker from turn to turn and you would never get to use your top speed advantage because the pond size dictates top speed,so,the quicker prop,not the top speed prop would rule the day here.Point being,you must match the prop to the situation at hand.There is no 'perfect 'prop for all conditions.But just sitting there,cavatating in the middle of the pond and over heating your boat is a frustrating ordeal that most people would rather not deal with.Just watch any pro drag race and look at the time slip at the end of the race,most winners have a quicker time and less top speed.I'll take quick most of the time unless the coarse is VERY long.

I dont really pay allot of attention to how a prop cavitates on take off because in racing you have ample time to get her up and on plain.It is important that you know if it cavitates so that you dont blow your start because your boat is still in the infeild looking for some bight.

I only pay attention to it when that's all it will do is cavatate, like it did when I first put it in the water,it's important to know that this kind of severe cavatation will cause your esc and motor to burn out very quickly,because there is no water flowing thru your system..a good setup is important along with the proper prop selection.

Thanks for verifying.
Let me pick your brain now....!
1. Smaller prop dia means higher rpm.
2. On equal boats/setuups: An x440 would be quicker out of the hole than a x440/3 just because 2 blades spin quicker faster. Now, the 440/3 will eventually win over the x440/2 if the course were wide with long straits because the 440/3 is propelling a higher water volume.
3. On equal boats/setups: An x440/2 would most probably win over an x440/3 on an s-course using the same hydrodyn as above.

Your right Trunk.But a little cavitation shouldnt scare you off of a good prop that otherwise will give you good performance.

Yes,your right and I'm not abandoning my x440 prop as it is fast on the topend.but does cavatate some.This is a better prop on 12 cells but the 220 prather is better on 14 cells ,I will run a x445 just to get that quick turn to turn blast of accelleration .So I will swap props to suit the need at the time.As I said ,there is no perfect prop.