FighterCat's 41" Sprint Cat Predicament- PLEASE VOTE!

[FighterCat57]

I haven't quite decided if I should continue with the twin 2200Kv CC/Neu on twin Turnigy 180 ESC's or if I should go with a single Little Screamers on 12s. As a third option I have a single Lehner 2240/7 High Amp LK I could run on 4-6s. Always have a third option.

What I'm looking for is a 45-60mph boat that has a good amount of run time. Really, I would like as close to 10 minutes as I can get. More is better!

With goals like that, it's almost a guaranteed success.

Now for the predicament.

If I go with the Little Screamers, I'll need a custom motor mount and a full single cable drive/rudder strut setup.

If I go with the Twin Castle's, I already have all the drive hardware, rudder and mounts. I can start building now.

If I go with the Lehner, I'll need a custom motor mount and a full single cable drive/rudder strut setup.


So, I'm really torn, I LOVE twin cats and really want everything I own to be TWIN and am really disappointed that I can't run TWIN SCREAMERS in this hull, but know that the single screamer setup is a awesome setup too!

I'm also open to suggestions as this should be a fun thread, so type away, have not fear!

[FighterCat57]

I added a 4th option, which is to ditch the CC/Neu motors and find a pair of outrunners that will produce more power. (if that's even possible)

So there ya have it. 4 choices and a whole thread to make suggestions. I like suggestions.

[RCKong]

i think you will have a 50+mph boat with the 2200 kv setup on 4 or 5s. I would try those new leopard 40mm x 74mm 2200kv motors, and for under $100 a peice, they are quite a bargain too.

[Rumdog]

Why try those when he already has the Neu/Castles?

[RCKong]

good point !!!

[Fluid]

With goals like that it may not be possible. Ten minutes of run time is pretty unrealistic for a large boat and 60 mph. With 12S/10,000 mAh cells the most you can draw per cell is about 50 amps average. That's only ~1800 watts of power from the motor, so a single pack simply won't cut it. Even dual packs will probably not get you to 60, and a top speed of 45 may be a struggle unless you run part throttle most of the time. But that means building a lot of heat in the ESC, and ten minutes may mean a shutdown.

I'm not meaning to be too discouraging, just realistic. Lower you speed expectations to 35-50 and you should be able to do it. It will require heat management and intelligent driving, but it should be worth it. Good luck!


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[FighterCat57]

With goals like that it may not be possible. Ten minutes of run time is pretty unrealistic for a large boat and 60 mph. With 12S/10,000 mAh cells the most you can draw per cell is about 50 amps average. That's only ~1800 watts of power from the motor, so a single pack simply won't cut it. Even dual packs will probably not get you to 60, and a top speed of 45 may be a struggle unless you run part throttle most of the time. But that means building a lot of heat in the ESC, and ten minutes may mean a shutdown.

I'm not meaning to be too discouraging, just realistic. Lower you speed expectations to 35-50 and you should be able to do it. It will require heat management and intelligent driving, but it should be worth it. Good luck!


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Ah, the voice of reason. Actual calculations. Thank you sir!

I will be varying speed quite a bit on this boat. It won't be an all out running boat, so will need to build accordingly. Needs to accelerate often and sometimes sit for a bit in the water while waiting for real boat traffic. Some slow speed use as well, so will need to be versatile and able to dissipate heat easily, even if that means adding a water pump to run while sitting in the water.

[DISAR]

Difficult decision, the best thing would be to try something which is arleady tested. Twin motors will give you more speed and less amps. I would go with the two castles, and if no good then with two others, cheap like Turnigy 1100 outrunners or expensive like 1521 1Ys.

[Xfactor]

youll get the lowest amp draw with the screamer I can almost bet you cause a 457's on 12 s pulls about 120 and your speed will be 60-70

[Xfactor]

Youll spend more money on the twins.Especially castles if you got that to spend why not power it with 1 big neu?You got 400 dollars to spend on motors right. That should get you a nice neu. 1900 series to 22 hundred series

[Xfactor]

The choice should be easy the screamers are cheaper than the castle with more power a no brainer but two ls's is overkill. But if i have all that cash the go get a bonified beast a 2280. a pletti 350 or a neu. I told you u dont know what you want see.

[Xfactor]

Get you a Ls and a swordfish 240 and enjoy your boat spend your savings on good lipos or lith-ions

[Fluid]

...Twin motors will give you more speed and less amps...

Uh, no. It takes the same amount of power (watts = amps x volts) to drive a boat to a certain speed regardless of the number of motors. In fact two motors/props are usually less efficient than a single drive. The OP's issue is run time, and that is dependant on two things - the size of his fuel tank and how fast he depletes it. He can achieve his speed goals, but may fall a bit short on run time - or vice versa. But he'll have fun trying and he may make it! Isn't that what's important - fun?



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[FighterCat57]

Uh, no. It takes the same amount of power (watts = amps x volts) to drive a boat to a certain speed regardless of the number of motors. In fact two motors/props are usually less efficient than a single drive. The OP's issue is run time, and that is dependant on two things - the size of his fuel tank and how fast he depletes it. He can achieve his speed goals, but may fall a bit short on run time - or vice versa. But he'll have fun trying and he may make it! Isn't that what's important - fun?



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You bet your sweet ass! I'm having a ball with this stuff!


BTW- The Little Screamer fits in the sponson... But 26lbs in a 41" hull?

[Rumdog]

DO IT!!!!!!!!!!!!!!!!!!!!!!!! TWIN LS outrunners. It's a BIG 41" hull! Makes the LS look small. Make it FAST!