Im looking for a new Alt. and i wanted and opinion on how big i need. Right now i will have 1 eD NINE.1 1 eD NINE.2x will a 200amp alt be large enough?
the bigger the better. it'll give you plenty of head room and upgrading will still be ok.
wattage rms /12.6V = amperage of draw take that number and x it by 1.2 for class D amps or 1.4 for class AB amps. add that number for what your stock alternator is rated at and that'll give you a good idea of how large the new alt needs to be.