Fastest BL motor on 6 or 7 cells?
 

I run brushless in my Traxxas Rustler. I have two. One with the ss5800 and one with the Feiago 8s/8012 combo. I am not really happy with the top speeds any more. I want a motor to get me into the 40's on 6 or 7 cells, without using tall gearing. I run M2k's so that adds to the mix. I only bash so I do more running in grass which also makes the temps higher.

The reason for staying with 6 and 7 cells is because I recently got 4 pair of GP3300 for my emaxx that I also run in my rustlers.

Thanks in advance for the help.

With smaller tires, the Feigao 380 size 6s should push your Rustler pretty fast. Or, if you want good speed, runtime, and power, you can get a Feigao 540 size 12s, and run it on 12 cells NiMh (14.4volts) or 4cell Lipo (14.8volts). This is the setup I run in my Rustler, and I couldn't be happier with the runtime and power.
Basically, you want the most efficient motor you can get, so you can gear it up more without it getting as hot. One thing to keep in mind is that higher voltage (when paired with a slower motor) will give better efficiency than lower voltage and a faster motor.

I dont think that the feigaos are the best to go with 6-7 cells, but a Lehner Basic 5300 or Basic XL 5000 will surely satisfy your need at such cell counts.

lehner gets my vote

lehner gets my vote

The Feigao 380 6s is faster than a Lehner 5300. The Feigao 380 7s might even be a better choice for the Rustler. The 7s is still slightly faster than the Lehner 5300, and is only 1/2 the price!

Since you running big tires and through grass. I think the 5000 xl might do you better justice. It has more torque over the basic to pull the tires and grass. JMO

Like I said, I am only going to be running 6 or 7 cells. I don't have smaller tires so M2K's are the only way for me to go. With that said, Do you think the 380 7s or the xl5000. What kind of adapter would I need to mount that 380?

From my experence. The bigger motors seem to push a truck with ease. There fore you get cooler running and more power. If the motor has more power you can run a little taller gear. JMO

What kind of amperage draw does the xl5000 have?

Another site says 125. I don't think that will work if it is correct. I checked another site and it came up the same. I don't think esc will take that. Sorry dude. I should have researched more before hand.

Is there any way you can run more cells? That would help the power and efficiency.

The XL5000 would not be a good motor to run, IMO. A Feigao 540 7s would be pretty powerful. It's kv is about 5000, not as fast as a Lehner 5300, but should have more torque. It should push your Rustler to about 40mph on 6cells without getting too hot.

Well, it has to be either a Feigao 7s or a lehner basic 5300, but I still think the 5300 will spool up faster than the 7s, since it has a shorter rotor. Just use a reasonable gear ratio and dont go too far.

I thought the 7s would be a hot motor like my 8s.

If you have two 6 cell packs wire them in series. Your motor options would be greater. Is this an option bigair.

Probably you've used long GR to make the motor heat up.

12 cells is not within his option.

I have gearing set to 15/87 and the 8s gets pretty hot after a good bash. Cuts off sometimes. Can the 7s really be that different?

No, 12cells isn't practical when you are bashing. I jump alot so I don't need the extra weight.

If the 8s gets hot and shuts off. I think the 7s will make it worse. 9s will work better as far as cutting off. But it will slow you down. Have you tried to gear it a little lower to see what happens. If possible check with temp guage.

Well, as I said befor, the Lehners are the best and you can consider buying the Basic 4200, too. With 7-8 cells, the 40s are within your grasp. And once again, use the appropriate GR.

Check your drive train and the bearing as well, for they can over work the motor if there is something wrong with them.

Nothing is binding, just cleaned and lubed everything.

So what is our conclusion? 5300? I thought it was a hot motor as well. Feiago 380? Will it push the M2K's? What will I need to push the XL5000? I want to be able to keep short gearing?


Thanks for the imput so far.

Another possibility of why your 8s is getting hot is undergearing. 15/87 is way, way low and you might need to add another cell and make the FDR from 15/87 to 18/87 and you can tell us how the whole thing go.

Yeah, do gear up. You will get more speed, and your setup will feel more powerful. You are running gearing that should be used for 7-8 cells.

The problem is the tyres your running. A 380 motor won't push them (I've tried with a Feigao 9s on 7 and 12 cells, it worked but not well). You need a hot motor like the XL5000, 7s etc to pull the amps you require. Which means either a really big fan on the controller, or a new controller.

I use a 6s on my trucks on 7 cells quite a bit, pushes M2K's with ease into the 40's on my T3. On 8 cells 50mph is achivable with this motor. Although it is too hot for your controller.

The mgm 16016 would handle the xl5000. I would try the gearinng to see before you go and spend more money. Just a suggestion. Keep us posted. Always like to hear the out come of a problem. Makes me smarter. :)

I'll try gearing up a bit. Thanks for the info guys.

Have you got a tempgun? normally a BL setup has got sweetspot. (gearing can help you out in this)

The XL5000 will be very, very hard on your batteries. what's the weight of your car?

Don't get the xl5000. You won't need it. Many people underestimate the power of the basic 5300. You should be able to do rolling wheelies at 30 mph. It's been done in a stampede which has similar sized tires.

If you stick with your 8s, gear it way up. It reaches it's max efficiency at 79 amps at 7.2 volts. (When iron loss = copper loss)

Yeah, i too won't recommend the XL, that 5300 pushed all kinds of cars around pretty fast..

I told you from the beginning to use the 5300 motor or the XL 5000, but since it sucks up 125amps then the 5300 is your ultimate choice, but gear up your truck from 15/87 to 18/87 first of all and then inform us as soon as you complete your work.

okay, I just went out and test drove it. I geared up to 18/81. I know that was a little extreme, but it's cool out so I figured I give it a try.

First I want to say that I am really liking the 8S motor. It's got all the power I need. I think my problem is this MGM controller.

Right off the bat not even 10 seconds into it the trucks starts cutting off. I hear two beats and it comes back on. Sometimes it's one beat and I'm ready to go. I didn't even have a chance to get it warm. It just kept cutting off.

Does anyone know what is happenining. I thought I got the programing correct. Now I am rethinking it. Any help would be greatly appreciated.

Your problem could be that the motor is pulling too many amps, and the MGM controller is activating its current limiter. That gearing may be too high, something like 18/87 might be better. Also, the 8s is rated at a pretty high number of amps, more than the MGM 80amp can handle continuously.

That's cool, at least it isn't smoking.

If that is the case then I need to get something stronger. I don't really like the programing of the MGM, to confusing.

Can mike get the schulze u-force 75?

FOR SALE: MGM 8012

Dont go for the Schulze uforce its weaker and priceier, but go for the mgm 16016. This thing is a great controller.

At least you making head way big air. What happens if you be easy on the trigger? Does it still cut in and out like that?

the 75 is strong, from what i've read.

It only gives 75 amps contiuous and 100 amps surge plus its worth 280 dollars. The mgm is 160 amps cont and 200 surge plus its 265 worth.

But the 16016 still has that funky programing though/