Fuse and wire gauge size for whole system

So I’m a newb when it comes to large scale electrical. I’m looking at installing a third amplifier and am curious if the 4 gauge wire I have running to the back of the car would be enough to power it with the other two amplifiers I have? I currently have the 4 gauge wire going into an 8 port (4 - neg., 4 - fused pos.) distribution block so I’m not too concerned about fusing capabilities and the amp requirements in that region. I have two Alpine MRV-F340’s (can’t remember what the rms is off the top of my head but not much if I recall 55-65wx4 maybe) and am looking at getting a Pioneer GM-D8604 (300wx2 rms bridged). I was informed back in the day I would have plenty of power to upgrade but I don’t know if I am pushing my limits now.

My next question is fusing the whole car up near the battery and having a small distribution point up there. If what I am reading correctly…would I just add the amps together of every device and get a corresponding fuse? Preferably ANL. If I am just doing the amplifiers for the stereo that’s 30a + 30a + 80a = 140 amps? Then if I were to go a step further because I am anal about wires running every where off the battery, and I would like to have enough power to start my car, would I just go about adding the 80 amps for the alternator onto the 140 for the amplifiers? Being 220 amps all together? I have the ground upgraded to 4 gauge as well. I wouldn’t mind doing the starter and possibly upgrading the wire running to the fuse box under the hood but only by a gauge. I do understand it maybe overkill, my main concern is getting a fuse put in for the amplifiers in the front of the car and thought it might be nice to upgrade or at least replace the existing positive wires up front as well.

[QUOTE=GSG2Teg;2332590]So I’m a newb when it comes to large scale electrical. I’m looking at installing a third amplifier and am curious if the 4 gauge wire I have running to the back of the car would be enough to power it with the other two amplifiers I have? I currently have the 4 gauge wire going into an 8 port (4 - neg., 4 - fused pos.) distribution block so I’m not too concerned about fusing capabilities and the amp requirements in that region. I have two Alpine MRV-F340’s (can’t remember what the rms is off the top of my head but not much if I recall 55-65wx4 maybe) and am looking at getting a Pioneer GM-D8604 (300wx2 rms bridged). I was informed back in the day I would have plenty of power to upgrade but I don’t know if I am pushing my limits now.

My next question is fusing the whole car up near the battery and having a small distribution point up there. If what I am reading correctly…would I just add the amps together of every device and get a corresponding fuse? Preferably ANL. If I am just doing the amplifiers for the stereo that’s 30a + 30a + 80a = 140 amps? Then if I were to go a step further because I am anal about wires running every where off the battery, and I would like to have enough power to start my car, would I just go about adding the 80 amps for the alternator onto the 140 for the amplifiers? Being 220 amps all together? I have the ground upgraded to 4 gauge as well. I wouldn’t mind doing the starter and possibly upgrading the wire running to the fuse box under the hood but only by a gauge. I do understand it maybe overkill, my main concern is getting a fuse put in for the amplifiers in the front of the car and thought it might be nice to upgrade or at least replace the existing positive wires up front as well.[/QUOTE]

Nevermind, I found some formulas and charts.

I like having a circuit breaker to isolate the whole system from the battery. When designing selective tripping your total fuse rating may be on a higher trip time, but have a lower rating then the sum of your components. I have toyed with the idea of redesigning the distribution using fets or contactors instead of fuses.