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Old 01-15-2010, 01:17 PM   #1
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Default kv rating on brushless motors?

am i understand the kv rating on brushless motors? it seems that the lower the kv the more suited for racing it is. so lower kv = faster motor or vise versa?

i'm new to brushless so this would be useful knowledge in picking a motor
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Old 01-15-2010, 01:22 PM   #2
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KV is how many times the motor spins for every volt applied.

so a 3300kv motor, off an 11.1v lipo, spins at about 36,000rpm max.

while a 5700kv motor off 7.4 volt will spin at about 42,000rpm max.

a higher number motor will spin faster for the same given voltage.

opposite to what you said.
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Old 01-15-2010, 01:23 PM   #3
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Originally Posted by Southern_Rebel View Post
am i understand the kv rating on brushless motors? it seems that the lower the kv the more suited for racing it is. so lower kv = faster motor or vise versa?

i'm new to brushless so this would be useful knowledge in picking a motor
SEARCH!!! this exact question was asked ~ a week ago...

lower KV= slower, more torque
Higher KV= faster, but less torque

look for somthing under 5000kv for racing
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Old 01-15-2010, 01:32 PM   #4
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am i understand the kv rating on brushless motors? it seems that the lower the kv the more suited for racing it is. so lower kv = faster motor or vise versa?

i'm new to brushless so this would be useful knowledge in picking a motor
Your right about the lower the kv generely = more rmp from the motor ...
Or do it this way to get a rough idea multiply thr kv by how many volts your battery is

eg - 2s lipo (7.4v) and a 8.5 turn 5000kv motor

7.4 x 5000 = 37000 rpm roughly

so if you use a 3s lipo its 55500rpm and that very very fast so yo can mix and match batterys and motors and gear ratios to tour needs ....

Wat are you runnig ? off road on road ?
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Old 01-15-2010, 01:50 PM   #5
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Your right about the lower the kv generely = more rmp from the motor ...
Or do it this way to get a rough idea multiply thr kv by how many volts your battery is

eg - 2s lipo (7.4v) and a 8.5 turn 5000kv motor

7.4 x 5000 = 37000 rpm roughly

so if you use a 3s lipo its 55500rpm and that very very fast so yo can mix and match batterys and motors and gear ratios to tour needs ....

Wat are you runnig ? off road on road ?
off road...mainly bashing...i was looking at the tekin rx8/t8 combo 2650kv with 5000mah 4s 30c lipo giving 39220rpm. be going in a team associated rc8.
im looking for a good medium for torque and speed and from what a friend suggested i should go with the 2650 for that balance. let me know if i am incorrect in my thinking on this.

Last edited by Southern_Rebel; 01-15-2010 at 01:55 PM. Reason: adding info
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Old 01-15-2010, 02:02 PM   #6
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off road...mainly bashing...i was looking at the tekin rx8/t8 combo 2650kv with 5000mah 4s 30c lipo. be going in a team associated rc8.
Sweet sounds good to me ...

Im running the mamba monster 2650kv with a turnigy 5000 4s 30c in my ocm buggy and its nuts aye
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Old 01-15-2010, 02:11 PM   #7
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off road...mainly bashing...i was looking at the tekin rx8/t8 combo 2650kv with 5000mah 4s 30c lipo giving 39220rpm. be going in a team associated rc8.
im looking for a good medium for torque and speed and from what a friend suggested i should go with the 2650 for that balance. let me know if i am incorrect in my thinking on this.
Yea shuld be good mate im struggling to keep my front wheels on the ground and top speed is bout 110kph . get the batterys from hobby king got mine for $60 cant beat that price aye .... and iv tried hyperion to compare and thers no difference at all in speed punch or run time, the turnigys wernt even warm and the hyperions were warm
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Old 01-15-2010, 02:30 PM   #8
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the turnigys are the ones i was looking at. at first i was looking at the zippys but hear better things about the turnigys so i'm going that way. this is my first brushless conversion.

also i hear about people have just as good of luck with the drag brake and not even worrying bout the mech brakes.
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Old 01-15-2010, 02:34 PM   #9
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Default kv

I prefer lower kv with higher volts
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Old 01-15-2010, 03:49 PM   #10
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yeah, I'm planning on running a 2200kv, in a firestorm, off 4-6 cell lipo, with a 18 - 24T pinion...

should be... scary haha
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Old 01-16-2010, 10:27 AM   #11
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with more research and recomemdations i decided on going with the 2250kv from tekin redlin rx8/t8
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Old 01-16-2010, 10:56 AM   #12
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lower kv on more Volts = less heat if geared for the same speed as more kv with less Volts.

I am very happy with 1700kv motor on 5S.
4S is too much heat to worry about
6S can stress speed controls during braking
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Old 06-13-2011, 07:34 PM   #13
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Check out this video where we explain what is KV in your Brushless Motor.

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.
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