Mamba Max motor possible mis-labeled?

[BrianG]

I suppose it is possible, but unlikely. You could contact Castle and see what they say.

Even if it was mislabeled, you should still get some very good speed with the 4600 or the 5700. I'm getting a little over 45mph with the 4600 on 2s with wheel-spinning torque in my Jato. I even have the start power turned down and timing as low as possible. I can't imagine running it on 3s!

The 7700 is a very hot motor. That would probably be a 3 or 4 turn motor using the kv ratings of similarly sized S motors. Therefore, your batteries are probably unable to provide the current needed to get that moving under load. Sometimes it's bette to use a lower kv motor for extra torque and simply use higher voltage to get the speed you want. Plus, the added torque from the higher turn motors tend to be a little more forgiving with misgearing.

Originally Posted by MetalMan

Are your battery packs stick packs or side by side?

Have you calibrated the throttle with the endpoints on your radio set to full?

If all else fails, you can contact Castle on Monday and ask them what might be going on.

Side by side packs. EPA is set to full.

Originally Posted by BrianG

The 7700 is a very hot motor. That would probably be a 3 or 4 turn motor using the kv ratings of similarly sized S motors. Therefore, your batteries are probably unable to provide the current needed to get that moving under load.

That seems like a logical explaination, however I am experiancing no cogging at all... I would expect to see some cogging at a minumum if the batteries were not good enough?

What would one recommend for a lipo-pack? I'd like to run 3s at a minumum.......

Originally Posted by Bomb-Proof

what temps is it running, how good are your packs?

Just for kicks, I tried 14.4v just a few minutes ago, Iirc motor was 110ish, speed controller was 165. Speed is better, but definatly nowhere near what it should be....

[BrianG]

Originally Posted by fiero_silva

That seems like a logical explaination, however I am experiancing no cogging at all... I would expect to see some cogging at a minumum if the batteries were not good enough?

Not necessarily. Cogging is simply the ESC not being able to determine where the rotor position is by the back-EMF pulses. If it's turning, however little, you won't cog. What I'm thinking is that you are getting a large voltage drop on your batteries under the heavy current the 7700 requires. Oh, and you defintely don't want to run that motor at 14.4v, that's almost 111,000 rpm!! :eek: ...assuming of course that the batteries actually stay at 14.4v.

If you're looking for batteries for that setup, I'd go with something that has a large Ah and/or C rating to be able to supply at least 100A continuously with minimal voltage drop. Otherwise your lipos will heat up fast and may be damaged.

Personally, the 7700 is not sized right for that truck. Maybe in a 2-3lb vehicle. Don't forget; as kv goes up, torque goes down and that motor may simply not enough torque to get the vehicle moving at a decent speed. Again, I'd say go with the 4600 or lower kv motor, use higher voltage, and gear appropriately. I am almost positive you'll be satisfied.

Originally Posted by BrianG

Not necessarily. Cogging is simply the ESC not being able to determine where the rotor position is by the back-EMF pulses. If it's turning, however little, you won't cog. What I'm thinking is that you are getting a large voltage drop on your batteries under the heavy current the 7700 requires. Oh, and you defintely don't want to run that motor at 14.4v, that's almost 111,000 rpm!! :eek: ...assuming of course that the batteries actually stay at 14.4v.

If you're looking for batteries for that setup, I'd go with something that has a large Ah and/or C rating to be able to supply at least 100A continuously with minimal voltage drop. Otherwise your lipos will heat up fast and may be damaged.

Personally, the 7700 is not sized right for that truck. Maybe in a 2-3lb vehicle. Don't forget; as kv goes up, torque goes down and that motor may simply not enough torque to get the vehicle moving at a decent speed. Again, I'd say go with the 4600 or lower kv motor, use higher voltage, and gear appropriately. I am almost positive you'll be satisfied.

Yah, I'll most likely be buying the 4600 motor shortly... Oh well, My stupid mistake in buying the 'fastest' motor from the get go...:007:

I guess I'll have to find a 'lightweight' 2-3lb car for the 7700 to go in now... Maybe a light weight land rocket of a road car or somthing :)




Basically what I want, is for the thing to be almost undriveable because it has so much power... I want it to be stupid fast, wheely on command and be a challenge to drive because it has so much power........