In general terms when swapping out a 3674 2,000 kv motor for a 4074 2,000 kv motor?

[1945dave]

I know this is not a one answer fits all kind of question but what would you expect would be the result in changing identical KV rated motors but going up from a 3674 to a 4074 motor of the same manufacturer and keeping everything else the same. In particular I have two such motors and the 4074 is rated at 1750 watts while the 3674 is rated at 1100 watts. Can I expect lower temps and no real performance gain until I change to a bigger prop?

Dave

[mtbenjamin77]

more watts means more amp draw with the same kv and same prop but higher loaded rpm = more speed. you really need to know what your amp draw is so you dont overload your esc. what esc are you running?

[1945dave]

This is good. Yes more watts means more heat and more amps capable. But if we don't change the loading will the more powerful motor work less and therefore not pull more amps? Can somebody that may have done exactly this comment? Makes for an interesting debate doesn't it?

Anyway, I am running a Turnigy 120 on this setup but expect to go the the Turnigy 180 when it comes it. 4S power is still the plan.

Thanks,

Dave

[mtbenjamin77]

I think the real key here is the efficiency rating. If you have a larger motor that it not working as hard but it's total amp draw is higher than the smaller motor its a toss up....
i.e.
small motor max amps = 90, actual loaded amp draw 100% = 90 amps
larger motor max amps = 120, actual loaded amp draw 80% = 96 amps

if you have identical setups with different motors it still takes the same amount of energy to push the setup to a certain speed. the only variable that changes the required energy to maintain that speed would be your efficiency.

This is my theory prolly not worth 2 cent. but I did just order an eagle tree data logger so I can test this very issue. I'll post results once I've determined a conclusion.

[1945dave]

Eagle tree data logger. What exactly did you buy and where from? Sure seems like if I bite that bullet I can answer a lot of my own questions.

Dave

[b20btec]

You can purchase it here OSE. Get the version where you can solder your own connectors. I own one (V4) with GPS and I love it. I'm far from being an expert from FE boats but datalogging has helped me make setup changes to my boats, props, esc, motor, and strut. Honestly without it i'll probably be on here asking what prop is good etc.