best placement of batteries in 25" pince deep vee for maximum speed and best handling

[Matt_1234]

hi, i am trying to figure out the best place to put 2x2cell batteries in my prince 25" deep vee for maximum speed and handling. here is a picture of what i had in mind.what do you think of the placement????
also i will buying a leopard 2200kv brushless for this boat and it will be run on 4cell (2x2 cells in series) what do you think?? i wanted to get more speed than the stock 380 on 3cell cause i thought it needed to be a bit faster but im sure this will be faster than the 380 for sure. especially using 4cell??? and will the leopard heat up at all???
what do you guys think of that also??? thanks alot for your help
matt

[tunnelvision]

Get the center of gravity about 27 to 30% from the back of the boat with batteries and all. That leopard will be wicked on the prince. Would need to run on flat water as it will be a rocket. What speeds are you looking for?

I ran the stock motor to the tune of 35mph. I switched to a leopard 2860 2730kv with a x637 prop and run in the low 40s on 3s. All my temps are at or below 90 degrees after a 4 minute run. My next props to try are a x440 and x640. I think 45 plus is very doable with my motor. Its a monster for its size.

Another motor to consider is the supervee 27r 1800kv motor for a 4s setup. Very good power out of it and you could easily run in the mid 40s with the right prop.

[AlanN]

Put the cells in the middle of the hull. Motor will have to be either farther forward or back to accomodate the cell placement. Always try to keep the weight centered and as low as possible, especially on a small mono. CG on non stepped monos is always near 30%. Measure as tunnelvision has recommended.

[785boats]

Matt.
That's how I ran mine through its various incarnations. But you would be better off getting at least 5000mah 40C batteries for a bigger motor. That motor will need them, plus the extra weight will help keep the thing on the water.
Here's a pic of my old 'Bulletproof' when it had the Aquacraft SV27 package in it. She would run at 45mph in oval race trim with an X 645 prop.
Also had the Ammo2300 in it with an X437/3 blade prop going a bit quicker.
The guy I sold it to now runs an 8Xl in it with an X440/3 blade prop & it's faster again
Hope this helps a bit.
Paul.

[Matt_1234]

thanks, yeah ill be buying better batteries. 2x5000mah 2cells. the leopard 2200kv is going to be crazy on 4cell. Its going to cost me a bit for the motor but as long as nothing else stuffs ill be right cause i wont have any money left. Hey 785, boats how did your hull hold up?? I see you havent put any of that carbon sheet stuff down. Everyone seems to be doing it but i think the boat is strong enough to be honest. so i dont see any point putting that carbon sheet stuff down.

[Matt_1234]

so in other words do i put the batteries even furhter back than what i have in the picture?

[Matt_1234]

Get the center of gravity about 27 to 30% from the back of the boat with batteries and all. That leopard will be wicked on the prince. Would need to run on flat water as it will be a rocket. What speeds are you looking for?

I ran the stock motor to the tune of 35mph. I switched to a leopard 2860 2730kv with a x637 prop and run in the low 40s on 3s. All my temps are at or below 90 degrees after a 4 minute run. My next props to try are a x440 and x640. I think 45 plus is very doable with my motor. Its a monster for its size.

Another motor to consider is the supervee 27r 1800kv motor for a 4s setup. Very good power out of it and you could easily run in the mid 40s with the right prop.

Yeah I'm sure the leopard 2200kv will have plenty of speed. Enough for this size of boat lol. Yeah I'm not too sure what speeds I want. How fast do you think my 25" prince will go with the leopard on 4cell with the stock 35mm prop? Also will the motor heat up with that prop?? Thanks

[Skipster]

Matt
You are getting a lot of good info here.

Remember your 4mm flex and square drive will only take so much
power before you have some serious issues.

Money would be well spent on a drive line upgrade
while plunking all this dinero on batts motors and ESCs.

Just a thought, hope it helps.


since you asked
4 cell = 4 x 1.3 NiMh "cells" = 5.2 volts

5.2 volts on a 2200kv motor = 1140 RPM
with a 35mm prop - well
it might not get on plane??

now IF you mean 4s
Thats around 32,000 RPM -> very good for mid 30's maybe
the 35 mm prop might cavitate though.

I do not see any heat issues.

Remember your driveshaft size when ordering props
get the spacer collar if you order a 3/16 "drive shaft diameter prop.

[Matt_1234]

yeah i meant 4sell lol. yeah the only prolem with upgrading the drive line is that i dont have enought money cause i will get the leopard and the 2 batteries and thats pretty much all my money gone lol cause im only 15 years old without a job!!

[785boats]

Matt.
I didn't bother with any carbon. The hull is a tough little nut. But I did run a fillet of glass cloth & resin along the rails & the motor mounts.
It is also advisable to epoxy in a 3/16" ply transom doubler to strengthen the transom for more secure mounting of the gear on the back.
As for the props, the Leopard wouldn't even know the stock 35mm prop was on there & as Skipster suggested might cavitate a bit. But you won't know 'till you try.
A good prop for a motor of that Kv on this size boat is the X437/3 blade.
We run it on the Ammo 2300kv motor with the SV27 45A ESC. And I'm sure the Leopard will draw less amps than the Ammo to spin that prop. Mind you that's just a guess. I haven't tried one. Don't be tempted to go too big with the props as I split 3 of those square drive shafts in the early days spinning big props.
Cheers.
Paul.

[Matt_1234]

Yeah I don't think I will bother buying a stronger flex shaft untill it snaps lol. Also my mate when he owned this boat he put extra epoxy everywhere where there was epoxy to strengthen it. I don't think I will bother about putting The ply in the back because it seems to be pretty strong now so I will leave it. The only thing that worries me is that with the rudder I don't have the safety bolt I just have a normal bolt in it so if I hit a log I think I will be screwed cause the bolt probably won't snap is there any things that I could replace the bolt so I don't rip a big hole in the hull if I do hit a log? Thanks

[Matt_1234]

well i got my new esc today which is good. hopefully it will not stuff up on 4 cell with the leopard motor. still waiting for the 380xl to arrive so i can sell it straight away with the other motor and the 2 batteries. Hoping to get around the price of the leopard motor so around $80 for everything. matt

[Matt_1234]

hey everyone i am still stuck on motor choice. I want it to go around 40-45mph. which one of these motors would be better to get the prince to 40-45mph ?? leopard 36x50 2290 or the ammo 36x50 2300. both on 4sell. and also i dont really want too much heat running it at that speed.
here is a video of the same boat as mine with the ammo 2300 on 4sell. I believe 785 boats owned this boat then sold it. thats about the speed i want. http://www.youtube.com/watch?v=WNhjk...eature=related
answers will help alot
thanks matt

[Matt_1234]

i am leaning towars the leopard cause i rekon it wont heat up as much as the ammo when i use x437/3 balde prop and they should both be the same speed. let me know what you guys think about either the ammo or leopard??? thanks
matt

[Matt_1234]

or i could go the 8xl for even more speed but i think thats too fast then lol the hull wont handle it?? please let me know out of these 3 motors which one would be the coolest runner with a x437/3 blade prop and be the overall best motor. leopard 36x50 2290 or the ammo 36x50 2300 or the 8xl??? thanks alot