power wire length???

[Buck 5,000+ posts]

haha. makes perfect sense... i guess this is what i get for wanting a better system. lol... oh and one last ? if i do a run from the ground from the front batttery to the rear, can i still ground those batteries to the frame so basically like a double ground?? in way it sounds like it would be grounded better but it also seems like that could end up really bad.

You can, but I don't think it will make too much of a difference. Make equal runs of power and ground. 2 runs of power, 2 runs of ground.

 

[Buck 5,000+ posts]

Look at this from another thread:

Anytime you need 2 runs of POS+ wire, you need two runs of NEG- wire. Would you run 1/0 POS+ to your amp and then 8 gauge NEG- for your ground? NO! You always should use the same wire for the POS+ and the NEG-. Remember that DC electricity runs in a loop. Down the positive and back on the ground. Car grounds are not made to handle large electrical loads, therefore they have high resistance and you will have voltage drops because of it.
Also, on a side note. If you need multiple runs of 1/0, why not just run one run of bigger wire? It would probably be cheaper to run a single 4/0 than two 1/0 runs as well. I have seen 4/0 welding wire as low as $4.50/ft and is rated to 600A @ > 50ft runs.

Also the grounding in the rear will not hurt, but it likely will not help unless you have a ground wire failure. It is thought of as a good idea as a backup.

 

[rickymac21 10+ year member]

You can, but I don't think it will make too much of a difference. Make equal runs of power and ground. 2 runs of power, 2 runs of ground.

hmm sounds good to me... im just trying to get all my voltage up. i gotta redo my big 3 with 1/0 guage instead of 4 guage... i got my H/O alt and y batteries should be here soon... so once i get everying ill be sure to add another run of poewr and a couple runs of grounds... will i have to run the wire under the car or drill a bigger hole in my fire wall? the hole thats in there is only big enough for 1 run . lol

 

[n2audio 5,000+ posts]

For the best results, run the ground from the front battery. That way all your batteries and your alternator are directly connected to each other through copper. Copper=really good conductor. Frame=not so much.

If you're running megawatts and need 1/0 or larger that is probably true, but if you're running 4 ga pwr/grnd the chassis is a better conductor due to a much larger surface area.

I have not seen definitive evidence, but Esoteric Audio who would benefit from selling 15' of ground wire for every install claims the "average" chassis is equivalent to about 1/0 gauge. One of the engineers at carsound has gotten results closer to 2/0. JL says more like 4.

 

[loopkiller 10+ year member]

If you're running megawatts and need 1/0 or larger that is probably true, but if you're running 4 ga pwr/grnd the chassis is a better conductor due to a much larger surface area.
I have not seen definitive evidence, but Esoteric Audio who would benefit from selling 15' of ground wire for every install claims the "average" chassis is equivalent to about 1/0 gauge. One of the engineers at carsound has gotten results closer to 2/0. JL says more like 4.

I would say that most full framed vehicles have decent grounds, but unibody cars are terrible. In the end, why not be sure an run the dedicated grounds? If you are willing to spend thousands on amps and subs, why not run the proper electrical? If money is that tight, you might need to scale back the install. Better to have a proper install on a smaller system than have a mess of an install with bigger gear. Actually, the larger the system, the more important the electrical becomes.

 

[Lil Poot 5,000+ posts]

I would say that most full framed vehicles have decent grounds, but unibody cars are terrible. In the end, why not be sure an run the dedicated grounds? If you are willing to spend thousands on amps and subs, why not run the proper electrical? If money is that tight, you might need to scale back the install. Better to have a proper install on a smaller system than have a mess of an install with bigger gear. Actually, the larger the system, the more important the electrical becomes.

x1000

 

[Buck 5,000+ posts]

If you're running megawatts and need 1/0 or larger that is probably true, but if you're running 4 ga pwr/grnd the chassis is a better conductor due to a much larger surface area.
I have not seen definitive evidence, but Esoteric Audio who would benefit from selling 15' of ground wire for every install claims the "average" chassis is equivalent to about 1/0 gauge. One of the engineers at carsound has gotten results closer to 2/0. JL says more like 4.

Look at what he is running. I don't think he's using 4 gauge.

hmm sounds good to me... im just trying to get all my voltage up. i gotta redo my big 3 with 1/0 guage instead of 4 guage... i got my H/O alt and y batteries should be here soon... so once i get everying ill be sure to add another run of poewr and a couple runs of grounds... will i have to run the wire under the car or drill a bigger hole in my fire wall? the hole thats in there is only big enough for 1 run . lol

That's good. Um, I don't know. Not sure what your ride is like. You might want to look into an h/o alt if you really want to keep the voltage.

 

[IDSkoT 5,000+ posts]

no opinions??? i understand this is a pretty basic and probably common since question but I just wanna know from someone who has tested this with experience???

The physics of it goes the longer the wire, the more resistance, thus the less easily the current can flow through. But, you do what you have to do. In an ideal world, everything woulkd be close together, but since this isn't idea, the alternator's on the opposite side of the car, and even if you put the battery in the trunk, there's still a long power wire.

But, yes, the shorter the ground the better... and you can try to get the power wire as short as possible. But there's not really much you can do.

 

[loopkiller 10+ year member]

See here is what most people get wrong. The end point your electrical circuit is not the chassis. It is not the frame of the vehicle. If you are running of alt power, it is the alt case. If you are running on battery power, it is the battery that gave you the power. So when they say keep your grounds as short as possible, having a 6 inch wire to the chassis of a unibody car, way deep in the trunk, is not a short path. Yes your wire is short, but the path, through pieces of welded steel, is not a short path. In all honesty, a wire is almost guaranteed to be a better conductor than your chassis. How much better depends on the amount of current you are pushing. The more current you push, the more you would gain by having a dedicated ground wire.

 

[rickymac21 10+ year member]

See here is what most people get wrong. The end point your electrical circuit is not the chassis. It is not the frame of the vehicle. If you are running of alt power, it is the alt case. If you are running on battery power, it is the battery that gave you the power. So when they say keep your grounds as short as possible, having a 6 inch wire to the chassis of a unibody car, way deep in the trunk, is not a short path. Yes your wire is short, but the path, through pieces of welded steel, is not a short path. In all honesty, a wire is almost guaranteed to be a better conductor than your chassis. How much better depends on the amount of current you are pushing. The more current you push, the more you would gain by having a dedicated ground wire.

that actually made a lot of sense. i did have it all wrong then. lol.. thanks x100 !! .. well im definitly glad i decided to poast this thread cuz it definitly boosted my knowledge of the electrical deal of systems.. i always think i understand it, then i learn somthing new. its rediculas. haha. thanks though!

 

[rickymac21 10+ year member]

Look at what he is running. I don't think he's using 4 gauge.


That's good. Um, I don't know. Not sure what your ride is like. You might want to look into an h/o alt if you really want to keep the voltage.

yea. i am useing 1/0 gauge.. def not 4 gauge. hahaha. im not a complete idiot for whoever suggested i might be using 4 gauge. lol.. but yea i already have an upgraded alt. its not the best but its way batter.. bought it from mechman. its a dynamoXL 150amp alt.. it does somewhere around 110 amps at 1800 rms or somthing.. i lost the paper that showed the results.//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif ..