I have an Audiobahn A8002t bridged (800 watts @4ohms) to a pair of Audiobahn subs (also rated 400 watts each or 800 watts paired at 4 ohms)that will be going into a 93 Mercedes 190e with a.c., power windows etc. It has a 70 amp alternator and a really big battery. Will this alternator be large enough or will I need a larger alternator, and if so, how large?