4 or 8 gauge wiring

[TexasA&M 10+ year member]

Hi everyone -

I'm going to be installing the infinity 5760 6 channel amp in my boat pretty soon. I plan on running it to the four speakers and bridging in 1 sub. According to the amp instructions, it is rated at a max draw of 87 amps, with a min wire of 8ga.

My question is this - In my search through various wiring kits, I have noticed that the 8ga kits are 'rated' at either 40 or 60 amps, and include an according fuse. When I look at the 4ga kits, I notice that they are rated at 80 amps, and include an 80 amp fuse. Which one of these would you recommend? I've already got 8ga power and ground wire (got it from a freind) so all I'm having to buy is the RCA cable and a couple of other various things, bring my wiring total to around $30. I haven't been able to find a 4ga kit for less than $60, and then I'll have to add shipping on top of that.

What do ya'll think that I should do? Keep in mind that my power run is only going to be about 3-4 feet, as the amp will be under the back seat, and the battery is in the back next to the motor.

Thanks in advance,

- Steve

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[n2audio 5,000+ posts]

I think 8 ga w/a 60A fuse would be fine.

Running that short a wire will cause very little voltage drop even at max. current draw (which will never happen anyway).

8 ga = .000764 ohms/ft. x 5 ft. = .0038 ohms

.0038Ω x 87A = .33v -- anything less than .5v is ok.

On top of that consider you're going to be drawing more like 20-30A with music.

However - why not just go with 4 ga and have some headroom??

The 8 ga kit at wal mart is $20, the 4 ga is only $25.

 

[TexasA&M 10+ year member]

What all does that 4ga kit include? Is it just as good as a name brand kit off of the internet?

 

[Acidburn 5,000+ posts]

everthing you need except maybe speaker wire (not sure about that)

yes

 

[n2audio 5,000+ posts]

It does have speaker wire, and Schosche is a good brand.

I just remembered, I'm using the 8 ga Wal-Mart kit in my boat. Running a 90x4 amp. I used every inch of the power wire too - 17' I think. It works fine.