How many amp alternator do i need to give energy to too hifonics brutus brz 2400?

2400 watts rms at 100 percent effiency your is 200 amps, however your power system should put out more like 12.8 to 13.8 volts with engine on so even with the likelyhood of an 8 percent loss in power 200 amps should be plenty. Therefore your amplifier will likely draw around 200 Amps of power keep in mind thiers a good chance your car will draw about 60 percent of your stock alternators power so add 60 percent of the stock alts numbers to the 200 and you should have enough to run it. Preferable spec out the alternator a little higher than what you think you will need. Theres no problem with to much power, now to little is an issue. You will also want to beef up your power wires from the alternator to the battery as well as your ground wires from the alt and battery. This modification is called the big three and if your going to upsize your alternator you will need it. 0 gauge wire isn't near as heavy as people seem to believe, it weighs about 1 lb for every 2 feet of wiring.