front to rear neg. wire runs ????'s

[Spooney 10+ year member]

In my last car I had a hell of a time finding a good ground in the rear. I finally said screw it and ran a 2/0 negative run from up front off of the battery(big 3 was already done as well) . World of difference . The single best upgrade I have ever made for the electrical system short of an alternator. Grounding to the frame is acceptable but in my opinion the steel frame of your car is going to have more resistance than a big run of copper wire.

 

[tommyk90 5,000+ posts]

Depending on the vehicle, electrical system and setup a dedicated ground run might not be necessary.

The only time you'll see a beneficial gain with running a dedicated ground is if you have a lot of capacity up front, meaning big/multiple alternators and big/multiple batts. Most of the time a good frame will support what the electrical in the front of the vehicle can supply.

Personally, I run a frame ground to my rear batts AND dedicated positive and negative runs.

 

[splwj47 10+ year member]

Depending on the vehicle, electrical system and setup a dedicated ground run might not be necessary.
The only time you'll see a beneficial gain with running a dedicated ground is if you have a lot of capacity up front, meaning big/multiple alternators and big/multiple batts. Most of the time a good frame will support what the electrical in the front of the vehicle can supply.

Personally, I run a frame ground to my rear batts AND dedicated positive and negative runs.

shit man, havent seen you in a while. well ill have my 300amp alt up fround and a 55ah bluetop bat. will be running an m1s so i will have 3 runs for positive. so ur saying i should have a few runs of neg from front to rear and also ground in the rear to?

 

[mlstrass 5,000+ posts]

Just make sure they are individual ground points,not all on one spot,for batts

No, do them all at the same spot. I usually drill a hole in the frame or weld a bolt to it, so I have a single point for all grounds. I've seen noise issues with multiple ground points...

 

[mlstrass 5,000+ posts]

[quote name='jockhater2']I ran 3 runs of positive and 3 runs of negative.
why. because @mylows10 ; said it's what everyone at competitions do.[/QUOTE]

I hope that was a joke....

 

[dumpbeast86 10+ year member]

In my last car I had a hell of a time finding a good ground in the rear. I finally said screw it and ran a 2/0 negative run from up front off of the battery(big 3 was already done as well) . World of difference . The single best upgrade I have ever made for the electrical system short of an alternator. Grounding to the frame is acceptable but in my opinion the steel frame of your car is going to have more resistance than a big run of copper wire.

the steel frame is one big ground itself. the most resistance between two grounds would in fact be a big run of copper wire. i prefer to keep it short

 

[jockhater2 10+ year member]

[quote name='mlstrass']I hope that was a joke....[/QUOTE]

nope.
ask @mylows10 ; if you got a problem with it.
That is just what he told me to do.

 

[adas Pro Seller]

It honestly does not make sense to run 3 runs of 1/0 positive to the back battery bank, and just use a ground to the frame.

Your typical frame is about the equivilent to one 1/0 to 2/0 run from front to back in most vehicles.

That means with no equal amounts of negative current capacity, IMO, your wasting money on a extra postive run of 1/0, and missing the point

DC requires both positive and negative equally, and only as strong as it's weakest point.

A dedicated ground run is even more important when running High output alts 250a+ as relying on the engine block to frame to rear of a vehicle is not enough if your trying to charge 250+ amps continuous AND draw from the front battery.

Just saw prime example of this on a locals build. Tons of subs on 9k+ RMS, 6 battery bank w/buss bars, 350a alternator, doubled up big 3, 4 runs of positive to rear...and just a solid frame ground in rear....after minutes of demoing, his Negative side buss bar gets almost hot to the touch....positive side cold...and he can't figure out why his alt won't charge up the rear bank at 13v+...negative side is getting bottlenecked and alt can't efficiently charge up the back.

Hope that helps.

 

[jockhater2 10+ year member]

It honestly does not make sense to run 3 runs of 1/0 positive to the back battery bank, and just use a ground to the frame.
Your typical frame is about the equivilent to one 1/0 to 2/0 run from front to back in most vehicles.

That means with no equal amounts of negative current capacity, IMO, your wasting money on a extra postive run of 1/0, and missing the point

DC requires both positive and negative equally, and only as strong as it's weakest point.

A dedicated ground run is even more important when running High output alts 250a+ as relying on the engine block to frame to rear of a vehicle is not enough if your trying to charge 250+ amps continuous AND draw from the front battery.

Just saw prime example of this on a locals build. Tons of subs on 9k+ RMS, 6 battery bank w/buss bars, 350a alternator, doubled up big 3, 4 runs of positive to rear...and just a solid frame ground in rear....after minutes of demoing, his Negative side buss bar gets almost hot to the touch....positive side cold...and he can't figure out why his alt won't charge up the rear bank at 13v+...negative side is getting bottlenecked and alt can't efficiently charge up the back.

Hope that helps.

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif it helped me! Now I understand why I did 3 runs of pos and 3 runs of neg! I only did it because I was told to.

Thank you for explaining it!

 

[jockhater2 10+ year member]

It honestly does not make sense to run 3 runs of 1/0 positive to the back battery bank, and just use a ground to the frame.
Your typical frame is about the equivilent to one 1/0 to 2/0 run from front to back in most vehicles.

That means with no equal amounts of negative current capacity, IMO, your wasting money on a extra postive run of 1/0, and missing the point

DC requires both positive and negative equally, and only as strong as it's weakest point.

A dedicated ground run is even more important when running High output alts 250a+ as relying on the engine block to frame to rear of a vehicle is not enough if your trying to charge 250+ amps continuous AND draw from the front battery.

Just saw prime example of this on a locals build. Tons of subs on 9k+ RMS, 6 battery bank w/buss bars, 350a alternator, doubled up big 3, 4 runs of positive to rear...and just a solid frame ground in rear....after minutes of demoing, his Negative side buss bar gets almost hot to the touch....positive side cold...and he can't figure out why his alt won't charge up the rear bank at 13v+...negative side is getting bottlenecked and alt can't efficiently charge up the back.

Hope that helps.

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif it helped me! Now I understand why I did 3 runs of pos and 3 runs of neg! I only did it because I was told to.

Thank you for explaining it!

 

[mylows10 5,000+ posts]

Well I can tell you that when I upgraded my wires and ran 6 grounds frt to back and 8 powers frt to back. Then 2 short grounds off my disto block on my 2 powerbass xta 5000's I went from a 150.7 to a 152.8 no sweat and I could burp that in the lanes all day. It helps with current flow between the frt and rear batteries and helps charg the rear batteries faster. That's just what and how it worked for me helped me beat my closest rievel on the west coast. Who has only been beaten in competition in the lanes once in 7 years out here ( by me )

 

[mylows10 5,000+ posts]

Well I can tell you that when I upgraded my wires and ran 6 grounds frt to back and 8 powers frt to back. Then 2 short grounds off my disto block on my 2 powerbass xta 5000's I went from a 150.7 to a 152.8 no sweat and I could burp that in the lanes all day. It helps with current flow between the frt and rear batteries and helps charg the rear batteries faster. That's just what and how it worked for me helped me beat my closest rievel on the west coast. Who has only been beaten in competition in the lanes once in 7 years out here ( by me )

 

[keep_hope_alive Premium Member]

as mentioned, it really depends on the vehicle. if you have a solid frame rail from front to rear - use that. more conductive area there than what you'll run in wire. if your car has thin metal and a mulit-piece frame - then run dedicated grounds. you have to pay careful attention to how the chassis is assembled.

copper is more conductive than steel. running dedicated grounds is fine to do. in most systems it won't produce a difference. in SPL, it can't hurt... but in SPL you are pulling from the battery bank - not the alt. the alt is just charging the batteries, so the demand is much less.

heat is caused from resistance. it's wasted energy.

 

[tommyk90 5,000+ posts]

the steel frame is one big ground itself. the most resistance between two grounds would in fact be a big run of copper wire. i prefer to keep it short

Sorry, but this is incorrect. Copper will ALWAYS be a better conductor than steel, given a certain thickness. Most vehicles are made up of thin sheet metal, welds, and unibody construction. The only vehicles that can support decent current draw (200-300 amps) are FULL FRAME vehicles where the owner has also upgraded all the big 3 wiring under the hood as well.

Steel is a very VERY poor conductor of electricity. I believe copper is about 10x more conductive than steel, if not more. Factor in that most steel used in vehicles is not great quality AND is full of spot welds and you reduce that conductivity even further.

Keeping grounds short is an old myth. In actuality, by keeping your ground wire short and connecting it to the chassis or vehicle body, you are increasing resistance than if you had a direct copper connection to the front battery/alternator (where that ground originates from). No matter where you ground to in the rear, the electrical current still has to flow all the way up to the source. Electricity is a two-way street.

The reason that most people don't do it is because of the cost of additional wire and most often it doesn't benefit them over a sufficient chassis ground.

 

[splwj47 10+ year member]

so equal amount of runs from front to rear it is.