# motor KV ratings question



## godofcable (Nov 3, 2010)

So I'm trying to figure out which way to go...

I have a 1/18 mini late model, running in an open class, anything goes.

I picked up a 5400kv motor, and was going to run on a 2S lipo. I figured based on the size of our track (carpet oval) that it might be a good fit. However, im getting absolutely smoked in practice. I need to decide whether I want to go to a 7000kv or better motor, or go 3S Lipo with my current setup.

So I figured Math could help. Iknow there is a formula to determine motor speed based on volts, but I can't find it. Anyone have it handy?


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## ta_man (Apr 10, 2005)

RPM = KV * Volts (approximately, since RPm will vary depending on load)


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