I was trying to decide on a KB45 twin setup for my 32in catamaran.

Im thinking of doing a kb45 8l-1800kv on 6s
or
a KB45 8xl-1600kv on 7s.
It would be the same rpm but im thinking the 8xl would be a faster setup.

Let me know what you think would be best.

8L on 6s...............

Hey rebuilder which do u think would put out the most power.

Also i might just go for the 8l since ive heard good reviews and its cheaper.

Just checked, the 1800kv is listed as a 10L..............still, the 1800kv is what matters. People have run it on 6s with good results. I'm thinking the 10L because of weight..........it weighs quite a bit less than the 8XL. You're gonna need a pretty strong ESC..........i'd go with the turnigy 180a at hobby city...................the 120a will be too close for comfort. The 8XL can put out more wattage but in a 32" hull i think its overkill. What prop are you thinking of...........x440 - X442, somewhere in there?

As an option to think about, you could look at the Feigao 10XL or 11XL on 6s................i think its a little better quality motor and its not so heavy..........its a long 540 can. You could also get away with the much less expensive 120a turnigy ESC at only $69.

http://www.offshoreelectrics.com/pro...prod=fei-540XL

http://www.hobbycity.com/hobbycity/s...hless_Boat_ESC

Yea i have thought of the Feigao line but i was thinking big motors because im going to build a 38in Kiton and 40-42in cat in the future so i was thinking of a good setup that would suit them also.

i use a 12XL 1400kvin my 30" cat on 2x 3s lipo and it shifts, well it did before the rx gave up (at home thankfully while testing range) so ordered a 2.4ghz setup and waiting for delivery

Like I said above i need alot of power for when i move to a 40in Kiton and a 40-42in Cat

Has enyone tried them first hand the 10l and 8xl

I have the 8XL in a 45" vee....its a powerhouse. 6s...........

What are your temps like?

I have heard that they shim them to tight at the factory causing the endbells to get hot and to cause them to burn out.
On the offshoreelectrics forums i found one about the kb45 being modified and thats were they said its runs to hot because of the shims.

http://forums.offshoreelectrics.com/...highlight=KB45

The KBdeff. runs hot! I have a 8xl in my sw36 on 6s. Ihave not temp'd it but it's hot! Even with the end bells drilled out for ventillation and watercooled. Also the effeciency of these motors are low, making them "gas hogs" also. Offshore electrics quit carrying these and now carry the Feigao 580L instead. I personally don't recommend the KB, eventhough my SW36 gps'd at 56, I'd spend the money at least for a Feigao.

No way, that's 40,000 rpm on a KB45b motor.. It will smoke
these KB45 motors are amp hogs and don't like much over 25,000 rpm in boats, they make alot of heat
you would also need a 200A esc to be in the safe range with these big amp hogs

I may be pushin mine a bit, but its ran OK.............i only do 5 minute runs..............its been a while since i posted the "8L on 6s"........i think i meant XL..............mine is an XL on 6s...................

A better choice IMO is a 3674 9XL motor on 4-5s
the big KB motors are amp hogs
I have a 31" cat with a 9XL on 5s and it flipping screams!
But if you have the 6s batteries and want the bigger motor, try the 1200kv motor. That's about 27,000rpm unloaded
it will pull less amps and have less heat also longer runtimes

he is talking about the bigger 45 motors that pull alot of amps and do not like high rpms and that's still almost 36,000 rpm!
4s would be ok on the 45 motor

Mine is too.............a KB 45 8XL - 1600kv...............It hasnt had a problem yet(knock on wood)............I run it in 4-5 minute spurts.

What color is the can?

Blue................with a 6mm shaft to boot[:'(]

any pictures of that setup?

yep

wow does that rudder sit low!

Pic is deceiving...................................I'm beginning to wonder if you have any slightly positive comments in ya...............pickin me to death.?

well its a big boat!
ya got any videos of this big rig running?

i got the kb45 12xl, 1400kv in my 30" cat, aint had her on the water yet as its still freezing cold here, from what i have read (and on the motor mod) i'm going to remove the shims and see what happens, but my speedo does get rather warm, its a pentium 100a esc

i knocked the rear plate of the can (hold the motor in your hand and just tap the shaft with a hammer) when the magnet assembly comes out, you have 3 brass shims at the rear and 2 brass shims plus a nylon thrust washer at the front, take 1 shim from the rear and replace with another nylon thrust washer, put the plate back on and tap it home (lining up the shaft with the bearings)

On the bench, it runs a bit cooler so the next step would be to drill out the plates for ventilation
its a shame the shaft is'nt longer so you can put a fan on the end to draw heat away along with the watercooling jacket