high output alternator

[1990ranger]

ive recently added fog lights to my truck. the alternator holds up but im adding two subs and a bigger amp to my current system. i know im getting a capacitor. i dont no if i should upgrade to 120 amp alternator. if i do what should i replace or upgrade with it?

 

[Ranger4657]

replace big 3 wires... you could always just not use your fog lights while using system or visversa ... insted of a capicitor maybe look into a cap killer insted or an audio battery (higher discharge and recharge rates)...
a formula to use is Power(watts)=I(current)*V(volts) to calculate how many amps u wll be pulling with all your lights and system at max output plus about whatever the curent would be for your other accesorys. then add it all togthrer and if it excedes 90 amps (stock alt) upgrade your alt. and big 3 wires to 0 ga. (or whatever will match your total current draw/ alt output. refer to this table for wire specs http://www.the12volt.com/info/recwirsz.asp
i think our origional charging wires are like 10 or 12 ga which limits alt's output to 40-60 amps.... so you can regain 30-50 amps of output with big 3 wires.
....... or dont use them all at once. =]