That'll depend on what else you have in the car. For example, 2 100w spot lights will eat up 20A. Best thing is to try it. If you see lights dimming, then it'll be a good idea to get HO alternator. Remember, an amp will not put out 1100w until max setting.
yeah i dont really plan on going any higher then what i have right now only cause its what i allready have and i dont have the money to be spending on any other equipment as far as any thing else drawing besides reqular stuff i dont think i have any other accesioures no spot lights,extra computers or any thing like that just the deck,amp,and subs and like i said any thing that might draw normaly