Need help with buggy conversion

[glassdoctor]

Originally Posted by AAngel

I really hate being so ignorant about something that interests me so much.

I just don't understand. If the 12L would thermal the escs that you mentioned, how is it that a larger motor (ie, 7XL) that draws more current and has fewer winds going to run cooler? Is it just because the 7XL is so much more efficient that it produces less heat?

OK, well let me ask this. With a proper load, can I say as a general rule that an XL motor will always run cooler than an L motor with a similar kv rating?

Do you think that the MM can handle the 7XL without stretching it? Should I just go with the 8XL? I want my whole system to be comfortable.

Yes... in general an XL should run cooler with the same load. I think in reality the XLs run cooler because they can pull a higher gear at a lower rpm (wihta lower kv) in other words, guys have switched out an L for an XL.... but normally the XL has lower kv.

As for my 12L Hacker/Feigao... I'm not the only one who had the MM work where several others had failed. RotaryRocket had the same experience with his buggy, using a Pletty Maximum motor. And remember, my motor may be pulling higher amps than a normal 12L. I clocked it with my gps at 55 mph on an old 4s lipo. And this was geared 13/44... it did 40+ at 10/44. So I think this motor runs faster than a 12L is supposed to. If I geared that thing 18/46 with better lipos I wonder what it would do? 65+? :)

The 7XL does have fewer winds, but it's not a "hotter" motor. It does have more ability to pull high amps but it also has inherently more torque so it won't work as hard to do the same job as an L size motor. Check out the charts that show the resistance and idle current of some different motors... the numbers don't change much for a given kv... XL,L or S.
http://www.hackerbrushless.com/motors_b50constants.shtm