EMAXX with MM 7700 what LIPOLY should I use?

[glassdoctor]

I will answer your question and no slamming. :)

You can only run a 2s pack with the 7700. Keep them light which means it has to be a good pack. I would recomend a single flightpower 2s 4900 pack. Then make your emaxx as light as possible and run in only in first gear... and geared as low as you can get it.

Run stock tires or similar light tires (nothing huge like 40's moabs etc...)

BTW, this is absolutely the best forum for brushless info... the guys are only trying to help.

I have a few and installed a bunch of the Mamba Max systems. My first went into a T4. It was a 7700 system and I ran it on 3S lipo. Everyone told me that it wouldn't work, including the guys at Castle. Well, I ran it like that for a long time and nothing ever went up in smoke. It was, in fact, the fastest truck out at the lot where I ran it. That very same esc (not the motor) is now in my Monster GT conversion running a Feigao 8XL on 4S lipo.

The mamba systems are great. IIRC, Castle used a couple of them to power a Power Wheels Jeep at some show. They put out a lot of power. I can say that I found that the 7700 system gets finicky when it's really pushed to the limits. I wound up having the run a 12T pinion with the biggest spur gear I could find and the shortest tires available to make it all work.

You definitely don't have the right setup, but it is what you have. If I were you, I'd just run it. The worst thing that can happen is that you smoke it.

I think that the key (and the point that some tried to make) is that you need to put the least amount of stress on the motor as possible. Just keep in mind that if you toast the motor, it might take the ESC with it. Keep it as light as possible. If you have access to shorter, lighter tires, you might want to consider that. Start with the smallest pinion and largest spur that you can get, and then, if possible, gear up from there. Make sure that you keep track of temps as you go. Check it and do it often until you settle on a setup.

If you are the type of person that will do the right thing (unlike me, who would just run what I have NOW), then you do have some things to consider. If this is your first venture into brushless and lipo, the adventure is just beginning. I don't know if you've already bought a battery and charger yet. If you haven't, you'll soon realize that they aren't cheap. A good 2S lipo pack can run you about $150, I believe for something like a flight power 4900, or you could save some money and get a maxamps pack. They are good for the price. The thing is that you have to ask yourself how much good money do you want to throw after bad. The MM 7700 system was a bad purchase. Do you now want to spend another couple to a few hundred getting battery packs for it, and whatever else you're going to need? When you get the system that you should have, you'll be wanting to run 4S packs, or more. I'd imagine that you could use your 2S packs and run them in series, but I think that's a pain in the butt to do if you don't have to.

There was a suggestion made that you might want to consider; and that is to sell the 7700 motor and get a Feigao XL motor. The 8XL would be a good choice for a truck. You might as well take a step back to start right, rather than try to push a bad situation.