Any idea what this boat should do?

[ecoovert]

I have a Proboat Miss Geico. I'm using a Tacon 4074 2150kv motor with an HK. 180amp speed control on 6s with an Octura x645 prop. I would try a Leopard 4082 but I don't think it would fit. I know what some of you are going to say, but my temps with this setup have never even reached 120 degrees using an x642 prop. The x645 should not overlheat my setup but rest assured I will watch the temps closely.

Here is my question. I don't have gps. to put in the boat and was wondering what kind of speed I can expect to reach with this setup. The closest to this setup I could find on youtube was a guy using an 1800kv Castle 3424 motor on 6s with a 40mm prop. His gps speed was 58 mph. with the 40mm prop. I know no one can tell me for sure but I just wanted an idea. Based on the speed he reached with his setup . After doing the math, on paper I should expect to be able to reach 85 mph. Now I know the increase in speed is not going to be linear but it would seem that I should be able to exceed 70 mph.

Oh by the way, I did install an offset rudder as I don't like going that fast with the porpoising issue.

[Make-a-Wake]

What to expect...........????

For your motor to fry.

Thats WAY too much prop for that setup...........6s is even too much for the motor really. On 4s it may be able to handle the 645. I'd go 5s and an x442.......... That is just not enough motor to get it much over 50....if that.

[martin]

Agreed nearly 48,000rpm unloaded is way to much especialy on that prop.

[Rumdog]

Expect fire, heat, smoke,popped and/or bulged caps, and probably puffed cells. Run it on 4s with a x442, x642, m445.

[ecoovert]

I value your advice but if my temps are below 120 degrees on 6s what am I missing? I will say that I am not racing with this setup and I do slow down in the turns. I also find myself stopping often to wait for my wake to settle down as to not flip the boat. This may explain the lower temps. I can say though that on a calm day I have blown over several times and that isn't supposed to happen until you are aproaching 60 mph. I have had that happen even with a 40mm prop. With my x642 I often find myself laying off the throttle when I see the front end begin to lift more than I am comfortable with. My UL-1 used to run on a 3 blade 42x55 prop on 4s. The UL-1 motor is under 1 horse power. The motor I am using now is rated at 2600 watts or 3.46 horse power. One would think it could swing a larger prop or at least the same size prop on 6s. One thing I can say is even with the x440 prop I used to have on it this thing is way faster than my UL-1.

Of the examples you listed the closest you have to my setup was the Pursuit on 4s. Running it on 6s should yield over 65 mph. at least on paper. Keep in mind I am watching my temps and so far my temps have been well in the safe range. The highest temp I have ever gotten was 114 degrees and 112 on the esc.

[Make-a-Wake]

Its not all about "temps" since you are on and off the throttle, stopping a while etc....... The amp draw comes into this equation running that many rpms and a high pitch prop. I bet you are pulling 150 amps with the 642 on 6s.............a 645 is large and will most likely pop caps on the 180. If you are really wanting to try it then go for it since it is yours afterall. Let us know how it all turns out.

[ecoovert]

I havn't put the x645 on it yet and may not. I know this motor is rated at 120 amps which I must say is well below the 150 amps you mentioned. I could also say that at only $50 a pop I am not very worried about the cost of replacing the motor but I don't really want to go through that if I don't have to. Would a 4082 on 6s be able to handle the amp draw? If so how would I be able to get it to fit in this boat? How about if I put a 4074 1800kv. motor in there? what kind of prop should that be able to handle on 6s?

[ecoovert]

Ok guys, my 4082 2200kv motor is on it's way. I hope to install it next weekend.

[m4a1usr]

Oh by the way, I did install an offset rudder as I don't like going that fast with the porpoising issue.

Ride issues are one of the most inherent problems needed to be resolved before pushing your gear to its limits. Take the time to ensure your hull attitude is consistent before pressing it beyond normal performance. In other words, dont get the horse ahead of the cart. Take you time. We do want an update as to how your build goes. And a video if you can make one?

John

[ecoovert]

Thanks John, I have installed a home made offset rudder bracket. I have pushed it to over 60mph. and it rides very well at that speed. I seem to have the center of gravity dialed in well but I know the larger motor will move the c.o.g. more forward which should be better. I am moving my lipo packs quite a ways forward to keep the nose down with my existing setup. The new 4082 motor will add a little more weight to the front as well as setting slightly farther forward. This may turn out to be a good thing allowing me to center the lipo packs better.

[JackBlack26]

That video would be mine. http://www.youtube.com/watch?v=hSuLgLjTDNc. The outrunner makes a lot of torque and I could probably run a bigger prop than the one I ran in that video, on 6S. But to play it safe, I now run 4S with a 48mm prop in that motor and get way better results.

Here is a video of the same motor with an x445 on 4S. http://www.youtube.com/watch?v=x-z18v-PFac

And here is the last outing with the boat after being prepped for white paint with a composite 48mm prop. The motor was the warmest it has ever been at 130* with no cooling at all. ESC was 110*, but it ran like a bat out of hell and will be my final setup The bouncing the boat does now is from being on the verge of blowing over. Still running the stock rudder.

http://www.youtube.com/watch?v=OwBj_EGu5Sc

Now, as far as the 4074 motor blowing up on 6S, I don't know why people still speculate on that when plenty of my boating buddies run "high KV" motors on 6S all day long. All it takes is common sense and tuning, I.E don't over prop! Hell, I ran 6S when I had my Gen with a 2200, T180 and a 40mm prop and that's a way bigger boat.

As far as getting rid of the "wha, wha" it's been proven time over time that finding the correct CG will smooth out the boat. People usually tend to mount the batteries to the rear of the 9" the manual states, when in fact you need to mount them forward.

[Rumdog]

No speculation. Nobody said the motor would blow up either. Why run a tiny prop, the esc at it's limit, and motor bearings at their limit just to push it inefficiently with said tiny prop? 4s, correct prop = fast, and reliable. How many guys need to pop esc's before they admit it's not a good setup?
90% of all these newbs lately are doing this same thing in their Spartans? Why? I know exactly why. Because if their Revo or Emaxx can do it... why cant a boat?!

[ecoovert]

You are so right about the C.G. I put my lipos way forward and that seems to work well for me. I'm now installing a 4082 Nemesis Gold 2200kv motor which not only should give me tons of power but also will move the C.G. forward some.

The only problem is it doesn't look like I'll be able to use the sub hatch. Any ideas as to how to make the sub hatch fit over the 82mm. motor? I've already pushed the motor back as far as it'll go without cutting into the wooden frame that the motor mount bolts into. If I can heat up the sub hatch enough I may be able to re shape it enough to fit over the motor. Don't know if puting it in boiling water would heat it up enough to accomplish this. The outer cull fits just fine and I know I can tape it which I already do anyway. I just like the idea of having something under that flimsy cull in case of a blow over which I'm sure is likely to happen with this power plant.

[JackBlack26]

No speculation. Nobody said the motor would blow up either.

Really???

What to expect...........????

For your motor to fry.

Maybe you should read the whole thread before replying, like you usually do.

Why run a tiny prop, the esc at it's limit, and motor bearings at their limit just to push it inefficiently with said tiny prop? 4s, correct prop = fast, and reliable. How many guys need to pop esc's before they admit it's not a good setup?
90% of all these newbs lately are doing this same thing in their Spartans? Why? I know exactly why. Because if their Revo or Emaxx can do it... why cant a boat?!

I don't know what ESC's you're talking about popping, but I have yet to kill the T-180 that I have used to experiment with max voltage and high KV motors.

Have you tried high RPM setups? There is plenty of tuning involved regarding prop size and ESC timing. And as far as being reliable, I have seen plenty of ESC's go out on 4S set up for what you call "reliable". The fact is that electronics will fail specially with what we ask them to do. What may seem "stupid" in your eyes may be enjoyable to myself and others. Pushing the boundaries proving the negative Nancies wrong. You have your opinion on why you think people run their electronics at their max so there is no real need to try and explain it any further. Bottom line is, if my equipment didn't cost you a dime, then don't worry about what I / we do or how I / we run it. .

[JackBlack26]

You are so right about the C.G. I put my lipos way forward and that seems to work well for me. I'm now installing a 4082 Nemesis Gold 2200kv motor which not only should give me tons of power but also will move the C.G. forward some.

The only problem is it doesn't look like I'll be able to use the sub hatch. Any ideas as to how to make the sub hatch fit over the 82mm. motor? I've already pushed the motor back as far as it'll go without cutting into the wooden frame that the motor mount bolts into. If I can heat up the sub hatch enough I may be able to re shape it enough to fit over the motor. Don't know if puting it in boiling water would heat it up enough to accomplish this. The outer cull fits just fine and I know I can tape it which I already do anyway. I just like the idea of having something under that flimsy cull in case of a blow over which I'm sure is likely to happen with this power plant.

Before I destroyed my stock hatch and got a Tiqueman composite hatch, I heated my sub hatch up and formed it around the rear of the motor. What I did was place the sub hatch on the boat then used a heat gun to slowly heat the bubble while pushing down on the sub hatch until it formed around the motor and locked to the hull. Now with the stronger hatch I don't use the sub hatch. Only reason its there is because the stock one will eventually break.

Good luck and post video!