Looking for mod ideas for MG 29

[ecoovert]

I'm looking for advice on pushing my Miss Geico 29 beyond 60 mph. 70+ would be even better. At this time I am using a Tacon 4070 2150kv. motor on 6s or 22.2v. The speed control I'm using is the 180 amp Hobbyking speed control. I also have the same motor in 2000kv. that I can install to bring the rpms down. The props I've used are x440, x442, x642 and a Grim Racer 42x55. I also have an Octura x645 that I'm affraid to install.

I've been told I'm over proped for this setup but my temps have never gone above 119 degrees. This motor is rated at 2600 watts or 3.46 hp. They say the max rpm of this motor is 60,000 rpm. On 6s the max rpm. should be just under 48,000 rpm. I know they say for racing you would want to keep the rpms in the 25,000-30,000 rpm. range. If I were to run this motor on 4s my rpms would top out at 31,820 rpm.

The stock 1500kv motor of this boat I think is rated at under 1 hp. If that's true with over 3 times the power I would expect to be able to push this boat to well above the claimed 40 mph I hear this boat is capable of.

I don't want to sound like an idiot but with this setup would 4s be able to give me the same power that 6s would? If so what prop would give me the highest speed. Is there a way to get the same power out of 14.8v as with 22.2v with a larger prop? If so which prop would be a good choice?

I would be open to an other motor but with over 3 times the power of the stock motor and 4 times the available amps one would think...

[JPriami]

Personally I feel 4074 1800kv - 2200kv leopard motors are too small to push the boat over 60mph safely. You can run in the 50's range on that and be ok but pretty much maxing it out.

HP in a boat is one thing but Torque matters a lot too.

I have other stuff I wanted to say but I'm pressed for time. Maybe some others will jump in and help out as well.

[ecoovert]

Thanks JPriami,

How do I know how much torque is needed and how much torque a motor has? I have no problem finding kv, max. cells, max. volts and sometimes max. watts but I don't recall ever seeing torque listed under the specs section of a brushless motor. Can you give me an idea of an affordable motor that would fit in this boat and meets the criteria of what I'm looking for? If you know where I can get one that would help as well.

Thanks again,

Eric

[ecoovert]

Hi there JPriami, Just thought you'd like to know I put the boat to the test last weekend. I ran it on a 600' measured distance and started from a dead stop. The boat took 6.5 seconds to complete the entire distance which comes out to an average speed of 65 mph. My max. speed could have been in the 70 mph. range. My temps never broke 115 degrees on the motor. the temps on the speed control and the lipos were lower but not by much. I do live in western Washington state and the high temp outside on that day was only in the high 70s. I'm happy with that. Even if the motor went I would only be out $50.00. and I do have a spare.

[JPriami]

What prop, motor, esc and how many cells again?

I'd like to see a video and you throw a gps in there as well.
Measured distances are a sure way to get speed calcs. But I drag race cars and you have to have a good setup to get accurate measurements.
If the gps is relatively close to what's measured in distance then that's great. But if not then there is probably some human error in how it's being done.

And honesty I just don't buy a 4074 making a proboat miss geico hull do 70mph without it ending in self destruction.

Just saying,

Sounds really fantastic tho and I'd love to see that. And congrats

Btw 600 feet in 6.5 seconds is 62.8mph

[LarrysDrifter]

I have a Leopard 4074 2200 kv with water jacket with 3 runs on it Ill sell for $100 shipped.

[ecoovert]

I understand that and that's why I was conservative in my calculations. It may be off by a little but when you consider this was from a standing start I'd bet I at least hit 65 and who knows if my calculations were off to my disfavor I might have gone faster than I thought. That margin of error could go either way. It could be partly due to the time I put into balancing and polishing my props... I don't balance props like the "pre balanced" props we can order from companies that balance props. You know who they are. Nothing wrong with pre balanced props but that's not good enough for me. When I receive those props I balance them even more. When I'm done balancing my props on my magnetic balancer no matter how I rotate the prop it doesn't budge at all. Using a balanced shaft also helps. Keep in mind I had installed an offset rudder bracket so the porpoising effect was gone making the motor have to work less hard. Call me stupid or call me a perfectionist but there a lot of things that can be done to add a little speed here and there. Keeping everything cool using larger diamiter tubing for the cooling system also may account for my temps remaing well within the acceptable range.

I understand a gps is the best way to go. I don't have a gps and that's why I didn't throw one in. If I could figure out how to use my cell phone for this I may consider it. You are also right about the actual distance/speed calculation. I don't know where I got 65mph. but the distance was more like 650' so I used 625' in my calculations to give some margin of error. Let's just call it well over 60mph. average speed and over 65 max speed; I can live with that.

[ecoovert]

Sorry Justin,

I might have sounded like I dissagreed with you in my last reply. I didn't mean it that way at all. All I am saying is the distance was more like 625' and it was from a standing start. all the rest of the reply was to show why I might have been able to reach 65 or so. I didn't use a gps as I don't have one. To tell you the truth not being made of money if I had to chose between a gps or a 4082 motor I would go fore the motor. I'd rather put the money into adding power or speed to the boat rather than try to prove to the world what the boat can do. I would also like to show a video from the shore of my boat in action but none of my friends who are into boats are able to come to the lake when I can and I'm having trouble finding someone to shoot the vid. for me. I do have a decent camera but am not confident in my ability to shoot video while I drive.

Thanks again Justin.

[wilsta67]

sit the camera somewhere where it can see the water and boat lol no need to hold it :-)
we like pics n videos around here

[ecoovert]

sit the camera somewhere where it can see the water and boat lol no need to hold it :-)
we like pics n videos around here

Ok, I'll see if I can get a chance to do that before we move to North Carolina. We're real busy packing preparing for the move on the 20th of this month. I sold my car to save on gas during the trip. Not having my own wheels at this time it may be hard to get to the lake before we move . I sold my car so we don't have to drive 3 cars. That would cost us an extra $700 in gas.

Sorry to say the closest place I can find to drive my boat where we are moving to is about 10 miles away. I hope to be able to get back into some wheels soon after we get there though. On Google Maps I found a place that looks great to run my boat. I would be able to park right where I would launch the boat and it appears to be public access. The only problem is it's aboput 10 miles away. I don't know how long it'll take me to find suitable weels in my price range. I now have a new member to my family, my dog Buddy and he didn't fit on the front seat of the car I had very well. That being said I'm going to be looking for a mini-van. That would be better for my dog plus it would be nice to have room for my boat, rc trucks, giant kites and KAP gear...

I'll see if I can get to the lake before we move but I can't guarantee anything.

[ecoovert]

I have a Leopard 4074 2200 kv with water jacket with 3 runs on it Ill sell for $100 shipped.

If you had a similar deal for a 4082 I might be interested. I can get a Nemesis Gold 4082 2200kv for $119.95 with jacket plus shipping. I found one place that has it in stock. I may have to jump on that deal.

[ecoovert]

Ok guys. I went and done it. I just ordered a Nemesis Gold 4082 2200kv motor. Don't know if I'll have a chance to install it and use it before my move to NC but rest assured I'll keep you guys posted. That will give me 3,500 watts to play with. or 1.2 horse power more than I have now.

[LarrysDrifter]

Ive been told the 4082 wont fit without a few mods. Just letting you know as I know the 4074 will fit without any mods.

[ecoovert]

Ive been told the 4082 wont fit without a few mods. Just letting you know as I know the 4074 will fit without any mods.

Thanks, I know I will have to shorten the shaft and mod the motor mount to be able to move the motor back just a tad. I know there is an 8mm. difference but 5mm. should do it and the motor mount should allow for that. If not I'll have to build a mount. I did order an extra motor mount in case I mess up on the first try.

[JPriami]

I know how you feel with not having friends that are into boats to record for you. Hopefully after you move you'll make some new friends that are into it. Or just move here and I'll have someone to run with too.

Sucks you had to sell your ride. I'd never get to go FE boating if I didn't have a ride. Because the best places for going fast are about 20 miles away for me.

Sounds like a good deal on the new motor. It should fit with the stock mount. Just reinforce the wood with fiberglass and resin with a couple layers and make it thick on the backside too. You prob won't be able to use the tupperware lid unless you put in a new mount or maybe heat it up with a heat gun and form it. I personally don't use one. I use hatch tape to seal my hatch on & keep water out. My canopy is also fiberglass reinforced.

You might could find a gps for around $40 used. I see them all the time on craigslist. I could use another one myself really so I should be looking too. But I've got other projects going and extra $ keeps getting used on those boats.