Gigaah

Ok. here it is. I have an RC10-T3. I don't exactly have a caliper so I don't know the motor diameter this truck will take.

I'm planning on going brushless for this guy. The motors I'm going through are not exactly marketed for land use.
They all have the motor dimension listed and the Kv rated(no not rated in turns like its seems most rc car motors are). I can get motors from less than 300Kv to well over 4000Kv so one of them should be suited(though I haven't figured out what Kv rating will work in a car vs what battery I'll be using).

The other thing is I don't know very much about where to get decent brushless ESCs for a car. It would be wonderfull if I didn't need reverse I could probably use one of my plane escs..but I do need reverse and brake.

Any comments or sugestions would be great! thanks!

green25

Theytake regular 540 sized motors.

Slo-V Flyer

Kv wise, how fast do you want to go? I know most plane motors top out at about 5000kv (for the smaller ones) and most car brushless motors start out at about 4000kv or higher. Basically if you want good 35-40 mph speeds running a 7.2v 6-cell nimh or 2-cell lipo, generally speaking you want a kv rating of about 6000-8000kv. 4000 kv is about the performance of most 19-27t brushed 540 motors, so you'll be looking at long runtimes and speeds of maybe 30 mph or so. Of course every motor brand is unique, and so kv ratings don't really tell the whole story, since there is also the factor of torque, but at least the kv rating will give you a guide line. Look at the Mamba Max motors to get an idea of what kind of performance people are getting using certain kv motors.

Gigaah

Maybe I don't exactly understand they way cars get geared.

Lets say I happen to get the 4000Kv motor you sugested. Can't I just change the gearing to make the vehical have more top speed and/or run 3s Lipo like I was hoping to? Obviously from what I gather by you that car motors generally are ran higher Kv. Is there a problem with gearing down a lower Kv Motor if it has the same wattage range as a higher Kv one?

Slo-V Flyer

you just don't want to gear it too tall like you would prop a plane motor too big. It will pull too many amps and oveall efficiency will suffer, plus you will lose the acceleration that the "properly" geared 4000kv motor woul dhave given you in exchange for slightly higer speeds. Higer kv motors are designed to handle more amps, which also lets them make up for the lack of torque by pulling more amps and are better suited for higher speed applications.

But to answer your question, if the ESC like a Mamba Max can handle 3s lipo as well as the 4000kv motor, then you can go a little faster (without gearing it tall by the way or you will possibly over amp the system), but it will still not be as fast as say a 7700kv motor on 2s lipo, though the 4000kv motor will still have more torque to work with over a broader rpm range (me thinks).