6S Tunnel hull ?'s

[Andris Golts]

Hi all i might have put the the cart in front of the horse with the previous post. ?#1 i have a Dunlap W.O.F 30 hull measures 29 3/4 '' in length the battery box will fit a pair of 3s 5000 mah lipo's no problem . Would this hull be suitable for 6s power ? ?#2 in the previous post i was told my rek 3.5 lower will not handle 6s power. What lower unit would be required to acomodate my 3674 1900 kv Leopard with .187 flex shaft for 6s preferably to adpapt to my Dubro 3.5 cc motor mounting bracket . Regards Andris Golts.

[Insanity Plea]

6s on a 1900kv will be 42,180 rpm =
5s on that motor would be a hot setup.

I'm not familiar with the hull but I imagine a 2200kv on 4s will be about the most it'll want. You should be able to reach 45mph with the right setup & prop, maybe more pending the weight of the boat.

This is a good outboard with .187 cable for a 30" hull.
https://www.offshoreelectrics.com/pr...dh-os-23871010

[HTVboats]

Looks like you have some equipment and want to use what you have. Assuming the hull motor and pair of 3S batteries are staying. Going to an OS lower will handle a 3674 easily with its .150 shaft. I have run 4074 and 4082 on that lower without failure. The OS has a skeg size sufficient for your hull and a better mount than your Dubro.. 6S not a problem on 1900kv but stay in the 440-442 and 642 range for props. 4S or 5S would be ideal and pull an M445. Now if you find a pair of 2S 5000 ma batteries to match your 3S you could do 4S-5S and 6S setups. On a similar size hull I have used a Castle 1415/2400kv on 4S getting 55+ speeds with an M445. 1415 is a 36X74 motor. Your Leopard should give you all your hull can handle. Small props will allow longer run times and not stress your ESC. Hoping you have at least a 120 amp.
Mic

[Insanity Plea]

I stand corrected, I was assuming 6s on a 1900kv would only be sufficient for short runs.

[HTVboats]

Insanity, you are correct as 5S or 4S would be safer. 1900 on 6S is a race or SAW setup. Propping back helps but your still spinning things at high revs and need to lubricate and maintain things. Remember loaded rpm will be 15-25 % less than no load. You can't pull as much diameter in props as you go higher in RPM.
Mic

[CraigP]

As a rule of thumb, the higher the kv, the more rpm's you lose life loaded. Lower kv motors run closer to unloaded specs, only about 10-15% drop off. That's given a like prop load.

[Andris Golts]

Thanks to all for the great info . Mic for the esc im installing a ETTI 150 esc i may re- think this set up and stay with 4s or 5s with the 1900 kv Leopard. Regards Andris Golts.

[Sheffield]

A guy build a Racemaster twin setup with Scorpion HK 3026 motors and 6S battery What a melody !

1400kv to 1700kv is the range with 6S batteries