[RwalkerRT22]

Hey everyone I was just wondering if someone has upgraded the big three in there nitro i am about to do it and was hopeing I could get a little help from someone who has done it before. thanks!

 

[KenCary]

Welcome to the forum, but you've got me stumped.

The "Big Three?"

What is that?

Ken

Ken

 

[RwalkerRT22]

its basically upgrading the three cables to a bigger gage wire...
1st is alternator to battery
2nd is battery to chassis
last is cable connecting engine ground to chassis

 

[KenCary]

its basically upgrading the three cables to a bigger gage wire...
1st is alternator to battery
2nd is battery to chassis
last is cable connecting engine ground to chassis

I can't see any reason why you would want to do this.

From an electrical standpoint, unless you put in a bigger alternator there is no advantage to doing this.

The guage of the wire is carefully designed by the OEM to carry the current without a significant voltage drop.

The highest current drain item is the starter, and it it turns this little V6-- it is good enough.

This idea sounds like pure auto voodoo.

Ken

 

[RwalkerRT22]

It is supposed to help with the electrical draw from running amps and subs

 

[KenCary]

It is supposed to help with the electrical draw from running amps and subs

What you are describing would be appropriate for some massive Electronic upgrade, but would be of little or no use for something in the order of 30-40 amps.

Again, if you are exceeding the alternator output of the Nitro, you'll need to change it and add a heavy duty alternator. Changing the cable size will not increase alternator output.

The other thing to keep in mind is that a high current draw-- say a winch or a killer amp, should be connected directly to the + terminal of the battery with its own fuse. In this case, the alternator cable will have no effect on peak current delivered to the device.

In many cases it is the peak current people are after so that the amp can deliver transient output peaks without clipping. Going direct to thre battery is the best way to cover this. A large capacitor is the second way.

Ken

 

[RB86]

What you are describing would be appropriate for some massive Electronic upgrade, but would be of little or no use for something in the order of 30-40 amps.

Again, if you are exceeding the alternator output of the Nitro, you'll need to change it and add a heavy duty alternator. Changing the cable size will not increase alternator output.

The other thing to keep in mind is that a high current draw-- say a winch or a killer amp, should be connected directly to the + terminal of the battery with its own fuse. In this case, the alternator cable will have no effect on peak current delivered to the device.

In many cases it is the peak current people are after so that the amp can deliver transient output peaks without clipping. Going direct to thre battery is the best way to cover this. A large capacitor is the second way.

Ken

i agree u should just get a good capacitor. i was pushing about 2500rms in my pathfinder a few years ago and i was having power issues to. my system once made my car actually turn off once lol. i just got a capacitor and problem solved.

 

[niftie]

I think that this is what you are referring to:
http://www.sunautomobile.com/products_hyperground.htm
It is very popular in certain circles.

 

[KenCary]

I think that this is what you are referring to:
http://www.sunautomobile.com/products_hyperground.htm
It is very popular in certain circles.

Any auto expert will tell you that this will do nothing to improve performance on a street car. The elctronics in modern cars are designed to work down to a fairly low voltage range.

If you are doing these things for some sort of high-draw mod--- like winch or killer strereo-- maybe there is some merit, but don't expect this to give you more power or better gas mileage.

Ken

 

[TylerCanada]

The Big 3 is the first step in a large stereo upgrade. A better battery (or a second one), and an upgraded alternator come next. My last few stereos were drawing in excess of 130 amps. At that draw, even 4 feet runs needs to be 4 gauge wire, and stock systems are almost always 8 gauge for the big 3. Unfortunately I can't help with the Nitro, as I decided to stay stock after too many break ins in previous vehicles.

Now, the Nitro alternator is a decently powerful 160 amp unit.

Oh, and grounding kits won't do much of anything because:
a) ground alone doesn't matter without also upgrading your alternator and the other "2" OR
b) people install them on a vehicle with an otherwise stock electrical draw

 

[KenCary]

If you are drawing in excess of 130 amps, the stock alternator will not provide enoough power.

As mentioned earlier, upping the "big 3" will be worthless unless you upgrade the alternator. Think this thing through systematically before you waste your time buying parts because someone else did.

Start with the power of the equipment you want to install, if the stock alternator is not at least 30% higher, go for an upgrade. Next look at the voltage range, that your equipment can tolerate. Based on this you can use a wire table to calculate voltage drop vs current. If you are returing via the Chassis ground, you will only have to calculate drop based on the positive wire, if you are using a foot or more negative cable, count that at well. It is the total voltage drop on the loop that you need to think about.

Again the battery and alternator cables are only one part of this calculation.

 

[RwalkerRT22]

thanks for all the info i'm still on the fence about doing it i purchased a optima yellow top battery but still have lght dimming issues i will let you know what i end up doing

 

[KenCary]

thanks for all the info i'm still on the fence about doing it i purchased a optima yellow top battery but still have lght dimming issues i will let you know what i end up doing

The Yellow top is a good choice, but it sounds like you are pulling too much for the alternator to keep up.

Keep in mind that the alternator does not put out full power at idle. You may have to upgrade to a larger alternator. In some cases, you will have to go to a smaller alternator pulley (if one even exists) to get more power at idle.

If you are seeing light dimming, I have a few questions to ask you and I can give you better guidance:

1. Do you have your amp wired directly to the battery? if not where is it wired

2. Does the dimming only happen on peak power-- like bass beats?

3. What is the total amp rating of the installed equipment?

Ken

 

[RobsNitro]

I have had the dimming lights issues before. But like it was mentioned before a Cap will take care of that problem. What sorta amp are you running?

 

[RwalkerRT22]

Hey ken thanks again for the help I Have power directly to battery its usually at peak bass hits. As for the current amp rating i'm not sure i have one mone 1100w memphis amp powering two kicker L7's

 

[RobsNitro]

Hey ken thanks again for the help I Have power directly to battery its usually at peak bass hits. As for the current amp rating i'm not sure i have one mone 1100w memphis amp powering two kicker L7's

I have sorta the same setup 2 12 kicker L7's myself and a MA audio 1200w mono amp. the lights started dimming after a few weeks when the bass would peak. before upgrading your alternator Id get a cap. I got 1.5 fared for a decent price.

 

[RwalkerRT22]

Does anyone know if it is possible to have to big of a cap

 

[KenCary]

Hey ken thanks again for the help I Have power directly to battery its usually at peak bass hits. As for the current amp rating i'm not sure i have one mone 1100w memphis amp powering two kicker L7's

Rwalker,

Your 1200W mono amplifier will probably draw over 100amps at peak. This is your problem.

A fully charged battery will put put out something like 12.7V unloaded and something 12V or less under a heavy load. The alternator is regulated to put out somewhere around 13.5-15V on most cars. The higher voltage is needed to push enough charging current into the battery. When you put a heavy load on the battery, the voltage will drop down to 12V or less as the load gets close to what the alternator is putting out. The dimming you see is a fluctuation between this 14V or so volts of the alternator and the 12V of the battery.

I could not find an output vs RPM curve for the Denso alternator in the Nitro, but here is an example of a curve for a heavy duty alternator on a Ford V10.
http://www.americanarmature.com/images/APSweb/AAI Nitro II G Engine Speed.pdf
Notice how max output is alternator is somewhere around 2,000 RPM. at 400RPM (idle speed) this 250amp alternator is putting out less than 50amps.

If we assume that the alternator in the Nitro can put out a maximum of 160amps, at idle it may only be putting out 40-50 amps. This is fine for lights, ignition and maybe the stock radio, but throw an extra 100amps at this and it is no surprise that you are seeing light dimming.

Here is where a big capacitor can help. If we assume your amp draws only 20amps for the bulk of the music, but 100amps on a bass beat, the dimming may last less than a second or so. A big capacitor 1-3Farads, can store power during the low power time and dump it out for the bass beats. This does 2 things for you, 1. May reduce light dimming on bass beats. 2. Will reduce clipping leading to better bass sound and help protect your speakers from square waves.

You should connect the capacitor as close to the amp as possible and use very heavy wire.

If you don't have a voltmeter, go out and buy one, this will help you fine tune your DC power system.

Ken

 

[KenCary]

You can't hurt anything by getting too big of a cap--- within reason. For a fraction of a second, a big capacitor appears almost like a short until it charges. If you had a huge capacitor or several in parallel (same thing) it is possible to blow a fuse when the capacitors try to charge. I don't think you'll have a problem with say 3-4 farads. Go up to 20 Farads and maybe you'll have a fuse blowing problem.

 

[TylerCanada]

A cap is a band aid fix. It's nothing more than a fast charging/discharging battery. If your alternator can't handle the average load, a cap will just make it last a few seconds longer before you get dimming. Do you get dimming when you rev to 2000 or 2500 RPMs?

With the 1000 watt system I had in my last vehicle, I could kill the battery in 20 seconds at idle. As stated, alternators don't put out much of anything at idle. What most people who can't get / don't want a high output alternator do, is to get a second battery just for the stereo. Make it a deep cycle (like the yellow top), put it in the trunk, and get a charging isolator (I can't remember the real name, it prevents the stereo battery from drawing power from the starter battery). It'll prevent dimming a lot longer than a cap will, and you don't have to worry about blowing fuses when you charge it the first time.