Do I really need 4 gauge wire to power a 400 watt amp?

[ledvedder]

Going from a lot of suggestions, I ordered a 4 gauge wiring kit to wire my amp. Man, that wire is thick! I couldn't find a spot in the firewall to run it from the battery to the amp. Couldn't I use 8 gauge to make it a bit easier to run?

[DoesDad]

How many actual watts are you going to be running?

[voltagexdt]

u can run 8 ga yes.

but heres what i tell my customers..

try to **** a milkshake through a coffee straw..
now try to **** it through a garden hose..

if you can get the 4 ga to work, when you decide to upgrade, your ready..

[mat3833]

run the 4 ga, technicly good 12 ga wire is rated between 35 and 50 amps constant current AC voltage(typicly ~40 amps is average). but bigger is almost always better. just go the 4ga run once and you will be set for ~130 amps constant(that works out to 1690W @ 13V) i went the "smaller wire first" route when i wired my first car. i ran 8ga and then 2 months later when i wanted to upgrade my sub amp and add a 4 channel amp for my comps i had to rip out the 8 ga and run some real wire. i wish i had just done it right the first time.

Matt

[quackhead]

Going from a lot of suggestions, I ordered a 4 gauge wiring kit to wire my amp. Man, that wire is thick! I couldn't find a spot in the firewall to run it from the battery to the amp. Couldn't I use 8 gauge to make it a bit easier to run?

this is why they make drill bits and rubber wire grommets....run the big wire.

[cdc351jeferson]

run the 4 ga, technicly good 12 ga wire is rated between 35 and 50 amps constant current AC voltage(typicly ~40 amps is average). but bigger is almost always better. just go the 4ga run once and you will be set for ~130 amps constant(that works out to 1690W @ 13V) i went the "smaller wire first" route when i wired my first car. i ran 8ga and then 2 months later when i wanted to upgrade my sub amp and add a 4 channel amp for my comps i had to rip out the 8 ga and run some real wire. i wish i had just done it right the first time.

Matt

Errrrrrrrrrrr wrong 12g is good for 20 amps 8 for 50 don't tell him this or you'll have his burned down car on you

[ledvedder]

Thanks guys! I guess I'm gonna just try running the 4 gauge.

[mat3833]

Errrrrrrrrrrr wrong 12g is good for 20 amps 8 for 50 don't tell him this or you'll have his burned down car on you

American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies and wire strength -_- actually you are wrong. the ONLY reason his car could burn down is if he was pulling more current than its rated for. and most wire is rated for AC current, not DC. and since AC current runs a bit hotter and causes more wear and tear(generalized term) a 20amp AC wire can safely flow ~30% more DC current. and i told him to just run the 4ga, so its not on me.

but since im not spechial, you can win this race bro. im not an olympian.

Matt

[sjv13]

Thanks guys! I guess I'm gonna just try running the 4 gauge.

Yeah, this is really the way do it. You will probably upgrade and/or get another amp at some point, and you will already have half the job done. That's exactly what happened for me. Was really happy I only had to do it once. Just put a nice grommet in the firewall and you'll be all set.

[cdc351jeferson]

American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies and wire strength -_- actually you are wrong. the ONLY reason his car could burn down is if he was pulling more current than its rated for. and most wire is rated for AC current, not DC. and since AC current runs a bit hotter and causes more wear and tear(generalized term) a 20amp AC wire can safely flow ~30% more DC current. and i told him to just run the 4ga, so its not on me.

but since im not spechial, you can win this race bro. im not an olympian.

Matt

Well you run 50 amps on a 12g tell me how it works for you

[mat3833]

if i had 12 ga that can take it, i would. the only thing that uses 12 ga that i own(asside from speaker wire for my tower speakers) is my poor mans lathe in my garage. the motor is powered by 6 volts@40 amps under high load. granted the length of wire is only about a foot. but i have yet to have a problem even after working with steel rods on the lathe. everything else electrical that i own runs the biggest wire it can fit. hell even my subs run 10ga or higher, and they only have 35W each right now.

Matt