Which motor is more efficient?

[champion221elite]

For an upcoming project, I'm torn between the following two motors.

Leopard 4082 rated at 1450 kv, Delta wound

or...

Leopard 4082 rated at 1600 kv. Wye wound.


Both are good to 33 volts and pull a max of 3500 watts. The 1600 pulls a max of 140 amps while the 1450 pulls a max of 128 amps.

This will be for a 30" catamaran hull as a dedicated 6s setup. I'm guessing the 1450 Delta wound motor could swing a larger prop to offset the reduced rpm's compared with the 1600 kv motor. By efficient, I'm referring to the most amount of speed, least amount of heat and the longest runtime if such a thing is possible. I understand that speed comes at a price, and that usually means heat and high amp draws, but hopefully folks know where I'm coming from.

[iridebikes247]

id go 1600kv. Big props aren't always the way to go, rpm is and especially if only a 30" hull. a 4082 with 1600kv will be more than efficient in that size boat.

[champion221elite]

Thanks for the insight!

[NativePaul]

What boat is it? Bigger, heavier and wetter boats will need a bigger prop to push them, whereas narrower, lighter and well aired out boats are less able to deal with the torque of a large single prop. Having said that most cats air out well but are wide enough to cope with the torque so either will work fine, some will say that Delta winds are amp hogs, I have found that to be BS, but Y winds do offer more timing options other than the "low" a Delta will need both are close enough that I recommend basing motor choices on KV not winds. Either motor will push a 30" cat very nicely indeed, so you can't really make a bad decision. Do you have any props already and if so of what size? I would personally go for the 1600kv version as I have more smaller props in my box than larger ones.

[Chilli]

Jeremy, I always pick motors based on the KV I'm looking for. I'm with Paul in that I don't concern myself with D versus Y winds other than programing the ESC. The two motors mentioned are pretty close in specs and the numbers as far as amp draw really don't mean squat. Both those motors can pull a heck of allot more than 140 amps. Also with a KV difference of 150, you're not going to be able to swing that much of a bigger prop. Motor efficiency is usually at a given load and RPM. The airplane motor manufacturers post this info but not the boat guys. That's because we push our motors way harder than the best efficiency point. It's hard for us to recommend a motor without knowing how fast you want to go or what kind of run time you are looking for. But like I said, there is not that big a difference in performance between the two.

[champion221elite]

The motor will be for a Mean Machine cat that I've found locally. I do have a selection of props available, and im hoping for a boat that will run mid to upper 60's.

[Fluid]

To reach the mid-60s you will need a prop with a pitch around 3". A Prather S230 or S235 would be good choices.


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[champion221elite]

I have a Y547 that is ready to go. 2.75" worth of pitch should be a good startng point.