mamba max on emaxx with 2 6s lipo packs (( HELP))

[redshift]

2200 x 25V(6S fully charged) = 55,000 rpm, you will want to gear on the low side with that kind of motor speed. As for exact ratio, we don't know if you have an old or new Maxx, but use the smallest pinion with the largest spur you have, that's the best starting point I can give you.