4drviper

A weird question, I was thinking.

If i wanted to draw 1200W from the engine to trunk, I googled and it said I need a 0gauge, for about 12ft of wire.
But my grommet in the middle of the firewall isn't big (barely fits 1/0 gauge) and it's already crowded with four 10gauge wires for trailer brake controller.


My question is, can I do this?
battery(+) ----3ft 1/0gauge-----2ft 8gauge---firewall hole---the rest(10ft?) 1/0 gauge -------distribution block.

I thought of it because 8gauge can support 200amps when under 2ft..

niebur3

First of all you are not drawing 1200 watts from a battery. I assume you have a 1200 watt amplifier you are using. Can you please post info about the amp, maybe even a link so I can see the brand, class and RMS power?

Now if it truly can produce 1200 watts at full power, then 1/0 awg (typically considered 0 awg), then 1/0 would probably be necessary (if running class a/b, which requires more current draw). If it is a class D amp, then 4awg would be plenty, as long as it is pure ofc (oxygen free copper) wire.

To answer your question, no. You can't go from 1/0 to 8 and then back to 1/0. You might as well just go 4awg all the way. You may need to drill a hole in the firewall and use a rubber grommet (sealing it to the metal) to get 1/0 all the way back.

Further, music is very dynamic, so unless you are planning on entering SPL competitions where tones are played, music will rarely draw max power from an amp, when set up correctly. So, even if your amp is truly 1200 watts and that is the only amp in your system, go with 4awg ofc and you will be fine.

4drviper

I was thinking of the 800W 120V inverter in the trunk

and
-from this part, it's purely daydreaming-
adding Focal KRX2 (nominal 100 peak 200) and 300ishRMS (peak 600?) of subwoofer.

niebur3

What would the inverter be for? Are you connecting a home stereo to your car?

Speakers don't make power, so power rating of speakers mean nothing in terms of what you need for wiring. It would only come down to the car amplifiers you are looking to use.

4drviper

lol James Bond laser and stinger launcher in the back :P

But whatever it is connected, I'm trying to slightly over-design the power cable so please assume maximum power.
I don't want to have surge on stuff when power level drops because my power wire is(was) barely enough.


anyway. power wire. 12V, 100A
because
3ft 1/0 = 0.167% loss
2ft 8 = 1.067% loss
10ft 1/0 = 0.833%
total about 2%


4gauge 15ft = 3.167% ..


meh, it's only 1% more ,, I understand if you said "it's not worth doing 1/0 and 8" but you said I "Can't."

Would you care to educate me why I can't have a small section of thin wire in the middle????



it's only 1% loss with 2ft length.. @ 12v & 100A

pohljm

Just leave it at you cant. your not going to understand the physics of electricity. If you want an analogy that you may understand think of the electricity as water and think about what your proposing conceptually.

4drviper

^ geez I'm trying to learn ._. isn't this where you ask and learn things? plus wasn't talking to you.

and I know it's LIKE water in some aspects but it's not water

pohljm

then do some research. we are not here to spoon feed you.

4drviper

^ well now I know you're not.

pohljm

http://www.physicsclassroom.com/Clas...uits/u9l3b.cfm

Kirk3272

iTrader: (1)

Run 1/0 only to trunk. Connect the trailer brank controller to an output on the audio fuse holder/distro in the trunk? Or there is another grommet in the middle of the car that you could move the trailer brake wiring thru.

NitroViper

iTrader: (2)

I agree with Kirk, run 0 gauge to the trunk and use distro block.

Putting a smaller wire in the middle will pinch the current. Imagine a garden hose, pinch it in the middle and it doesn't matter how big the remaining hose is, the pinch will restrict it. It is the same theory with electrical current.

Some of these guys here get their all mighty panties in a bunch, just forget them and move on

4drviper

I am currently using this hole, which is barely big enough for single 1 gauge,, looks like
https://acurazine.com/forums/showpos...31&postcount=3

I have 3 10gauge with extra thick coating through and it's almost full. Are you saying there is other easily-accessed grommet?? That would be great.

But I guess I can use distribution to the trunk to power the trailer brake controller. Thanks. I hadn't thought of that.

NitroViper

iTrader: (2)

Take the 10 gauge wires out and run one 0 gauge. Use the distribution block, it'll be easier and wont have 4 power wires running thru your running boards and 4 hooked to your battery. That cant look good lol.