4 runs?

[garretttt4 10+ year member]

Honestly that kind of stuff is basic when running that kind of power. I see burned up equipment in your future

I don't. Thats why I'm on here asking questions trying to do it right.

 

[djjdnap 10+ year member]

By the way its not the alternator, its the engine block that is the best ground.

 

[djjdnap 10+ year member]

The easiest way i see you running this setup would be.

adding another battery in the rear.

Running your runs from the front to the rear batt.

From the rear batt to the Amp.

The rear batt would act as a distro block and give you more reserve

 

[NASTY08IMPALA 5,000+ posts]

The easiest way i see you running this setup would be.
adding another battery in the rear.

Running your runs from the front to the rear batt.

From the rear batt to the Amp.

The rear batt would act as a distro block and give you more reserve

hes adding 3 batteries to the rear ..where the hell have u been ..the question is it worth making full ground runs from the front battery to the rear battery bank

 

[LosIsATool 5,000+ posts]

Weird. I always thought the frame would be best cuz its closest to being grounded. Idk in still a newb with electrical this is my first big build. So Im trying to figure this all out now so I don't screw anything up. If I did 2 runs of 1/0 + and1 run of 1/0 - and two - gnds in the back would that be good? Just trying to save some wire but I fess wouldnt save much in the end really if I already was doing 1 run of - to front......

By the way its not the alternator, its the engine block that is the best ground.

The alternator makes power. It flows out and pulls in. Not the engine block.

 

[dumpbeast86 10+ year member]

hes adding 3 batteries to the rear ..where the hell have u been ..the question is it worth making full ground runs from the front battery to the rear battery bank

nope

 

[LosIsATool 5,000+ posts]

Lets make this easy. Look at every successful moderate power build. What do you see?

 

[NASTY08IMPALA 5,000+ posts]

i see ppl regreting adding useless runs to gain .1 in voltage and little to nuthing on the meter

 

[djjdnap 10+ year member]

The alternator makes power. It flows out and pulls in. Not the engine block.

Pulls what in?

The alternator doesn't pull anything in it only generates power. This is not AC, well it generates AC, but thus the diodes in the alternator that convert it to DC.

Also if that was the case why don't Alternator manufacturers have a Neg post coming from the Alt?

But that is besides the point, even if you are correct the Alternator is still mounted to the block directly, So anything connected to it would still be sufficent

 

[LosIsATool 5,000+ posts]

Pulls what in?The alternator doesn't pull anything in it only generates power. This is not AC, well it generates AC, but thus the diodes in the alternator that convert it to DC.

Also if that was the case why don't Alternator manufacturers have a Neg post coming from the Alt?

But that is besides the point, even if you are correct the Alternator is still mounted to the block directly, So anything connected to it would still be sufficent

It's called a loop. And they do have a negative. The case

 

[dumpbeast86 10+ year member]

http://www.memphiscaraudio.com/documents/MC%20CLASS%20D%20MONO%20BLOCK%20SUBWOOFER%20AMPLIFIER%20MANUAL%20080818.pdf

page 6 explains how the amp should be grounded. same would go for the rear batts. this would all depend on doing a proper big 3 as well. just make sure you have the same negative capacitance as positive. 2 pos runs front to rear bank, then do two grounds at rear chassis. knu 1/0 is rated over 300 amps. 2 runs=at least 600 amps capacitance. 4000watts/14.4 volts=278 amps of max current draw with constant voltage. you can always add runs later if it tickles you, but most just don't need 'em...........

 

[djjdnap 10+ year member]

Second interesting thought.

I can run my car with no alternator.

I can also run my car (after starting) with no battery.

Also dc circuits power runs from neg to pos.

The only neg is the battery.

The alternator serves to charge the batt.

the neg cable is connected to the chassis(ie chassis ground)

I dont see where the idea of the alternator being a ground comes from when it is only a generator and the battery is what completes the circuit not the alternator.

edit:

The only thing i can see is that the engine block is cast iron v and aluminum housing which would conduct better.

 

[LosIsATool 5,000+ posts]

Second interesting thought.
I can run my car with no alternator.

I can also run my car (after starting) with no battery.

Also dc circuits power runs from neg to pos.

The only neg is the battery.

The alternator serves to charge the batt.

the neg cable is connected to the chassis(ie chassis ground)

I dont see where the idea of the alternator being a ground comes from when it is only a generator and the battery is what completes the circuit not the alternator.

edit:

The only thing i can see is that the engine block is cast iron v and aluminum housing which would conduct better.

Umm you can not run the car without the alternator. It's purpose is to run the car not charge the battery. Think of the alternator like a battery that charges itself.

 

[garretttt4 10+ year member]

http://www.memphiscaraudio.com/documents/MC%20CLASS%20D%20MONO%20BLOCK%20SUBWOOFER%20AMPLIFIER%20MANUAL%20080818.pdf
page 6 explains how the amp should be grounded. same would go for the rear batts. this would all depend on doing a proper big 3 as well. just make sure you have the same negative capacitance as positive. 2 pos runs front to rear bank, then do two grounds at rear chassis. knu 1/0 is rated over 300 amps. 2 runs=at least 600 amps capacitance. 4000watts/14.4 volts=278 amps of max current draw with constant voltage. you can always add runs later if it tickles you, but most just don't need 'em...........

So technically I COULD run it on 1 run.but it would be at its max right? Jw. I'm doing two runs enyways but ya.....

 

[dumpbeast86 10+ year member]

So technically I COULD run it on 1 run.but it would be at its max right? Jw. I'm doing two runs enyways but ya.....

yes you could do 1 run, reason you do 2 usually is because it helps with thermal capacity and because of fusing limits. wire i run is capable of 350+ amps, but you can only get a 300 amp fuse. so you do two runs to essentially cut the current in half. it won't always be exactly 50/50 per wire, but you get the idea

edit- i believe that manual said do (2) 250 amp fuses