The Mamba Max Pro will take up to 6S lipo
. Not sure what the motor limit is... but even running a 5.5T on 6S would be crazy fast. Not sure how you'd fit a 6S lipo in a BJ4 tho.
I may not be correct, but AFAIK a 3.5T running on 3S will be faster than a 2.5T on a 2S.