The question is how big of an alternator do you need? A capacitor will help, but if you are having stall outs this means you are depleating your alternator max output. I can guess that is only 75 amps or less. You can try upgrading your battery first, then put in bigger power wire if you need to. 2 gauge will be best. This will allow your amp to get full current not "starve". Then if you are running an amp bigger than 1000 watts it would help to run a 2 farad cap. Not under that. Any bigger will not hurt. But if you are able to upgrade your alternator that is your hugest upgrade and benefit. 90 to 100 amp is great!! Good luck!
