Which alternator is best?

DemonAstroth

My car has a stock 80 amp alternator. I suppose this is not while idling, although I could not find the specific info.

Anyway, there is a newer similar model car that has a 110 amp alternator, which since it is OEM I'm sure I could get for a decent price. Maybe less than $100?

or

I could buy an Iraggi alternator, they have two available:

180 amp / 90 amp idle for $260

200 amp / 90 am idle for $280

I basically only have two amps right now:

1) Eclipse 34230 Premium (370x2 4ohm @13.8v rms)
2) Eclipse PA5422 (85x4 4ohm @13.8v rms)


The only foreseable changes in my setup right now are to change the Alpine SPX's to some SR6500's. And maybe the Infinity Kappa Perfect subs to Momo's. Would I need an extra amp for that, if so please consider that.


So, which alternator do I need? If I raise the volume quite a bit my dash lights do start to dim, and I have an optima yellow top. I want to get an alternator that will do the job, but I don't want to get something that's overkill and unnecessary, as I'm a student and don't have much money.

Thanks all.

disneyjoe7

For $20 buck what the heck go big. Nothing different at idle but like the larger alternator to recharge battery or batteries when driven vehicle around. YMMV Just my $.02

DemonAstroth

That's if I have to go with the Iraggi, which makes sense as it is only a 20 dollar difference, but what about the 110 amp from a similar model? If that's enough to power my amps then the diference in price is like 150 dollars.

disneyjoe7

Well I got hang here to much, so if I give you something error they kill me

But the question I have is this is the original alternate given you trouble? Are you running the engine when you are given everyone you audio stereo

The question is if you're having some trouble with a small battery or a small alternate?

BTW my feeling is the old alternate is giving you 30-40 amp at idle the other one 110 amp my give you 35-45 amps at idle. I would go to a nice starter and alternate store who rebuild them right there and talk with them, they should give a nice answer for the idle amp outputs.

GLN305

I would definitely go with the larger Iraggi alt. I have one for my truck and had one for my last car and they were great. What kinda car and what size is the current alt?

DemonAstroth

I have an Infiniti G20.

There is a Sentra that shares the same motor (sr20de), which has the larger? (read more amps) alternator.

I really don't have any problems for most driving. Yet I find two things strange.

1) When I turn on the car, the lights in the dash are pretty dim, as soon as I rev it they come up to their full brightness. This is my 5th G20 and I never had that happen. I know it's not the battery because it happened with the one it came with, and it still happens with my Optima yellow top.

2) If the music is really really loud, then the lights will start dimming when the subs hit.

So I know that the alternator can keep up with loud music, but if I really crank it up it's having problems. I want to get a good alternator before I kill this one and my car is out of commission for a few days.

rskarvan

Remember, all the alternator does is keep the battery charged. If you vehicle lights are dimming, then the battery does not have enough "active material" to maintain system voltage. Now, most batteries can put out 800 amps when starting. So, rather than replace the alternator... you may want to just make sure your battery is sufficient. A bigger battery never hurts anything. But, a bigger alternator will place a larger mechanical power drain on your engine.

GLN305

Actually there is a little misinformation in this thread. Batteries are for starting and car-off use only. While the vehicle is running, batteries are a load on the alternator and the alternator runs everything. Now if you have a bad battery that is causing a larger load than normal on your alternator, then I can see a voltage sag problem. Getting a bigger alternator in that case would be a band aid for that problem. Have your battery and alternator tested and replace the bad item first, of course if you can afford both, it's a good idea. You may also want to upgrade the "Big 3" wires, which consist of a ground from the battery to the chassis, a gound from the battery to the engine block and a larger charging wire from the alternator to the battery. Of course you'll need to do #3 if you get the bigger alternator anyway.

Another exaggerated myth is that HO alternators cause a huge power loss at the engine. I know more than one person running 3+ alternators with very little noticeable loss. When I owned a Dodge Dakota, I went on a forum where the HO alt versus horsepower debate raged so long that someone dynoed their truck before and after installing an HO alt. I believe the difference was 1/2 a horsepower, which could have been the alt or equipment tolerances, either way too small to notice.

rskarvan

GLN305 wrote: »

Actually there is a little misinformation in this thread. Batteries are for starting and car-off use only. While the vehicle is running, batteries are a load on the alternator and the alternator runs everything.

GLN305,
This is entirely untrue. The alternator rectifier bridge monitors the system voltage. When the battery voltage drops below a certain pre-determined level (when the car is running), the alternator kicks in and supplements the system with a higher voltage to charge the system. Once the system rises above a certain thresh-hold, the alternator cuts off the the supply and lets the system run.

A good analogy would be that your alternator works sort of like a thermostat. It turns on when the temp (volts) drops below a certain level and cuts out when the temp (volts) goes over a certain level.

The BATTERY is the reserve where the power is stored.

If you don't believe me, disconnect your alternator (remove the belt), and your car will still run for about an hour or two strictly off the battery reserves.

- Ron S.

PS I worked as an engineer for Delco Remy for 13 years. Delco Remy manufactured starters, alternators and batteries for General Motors. I've also driven a few vehicles at highway speeds without a working alternator.

DemonAstroth

I do not believe the battery to be the problem. I can run the stereo off the battery for a long time with no problems. That is the reason why I went with a yellow top. The problem even started before I put in the yellow top, it had some walmart battery before.

If the alternator is not supplying enough power to power up the 2 amps plus the regular car functions, I don't see how upgrading the alternator would be a "band-aid" solution. Would I not be changing the "faulty" part?

It's really not that big of a problem, as soon as I rev all my instrumentation lights up just fine, and unless I want to go deaf the lights don't dim at all. I just want to take preventive measures before I have to fix it.

I don't care too much about the power issue. The car is one of the best handling cars, and it revs quite high (7500 redline)... so although the power stock (145hp) is kinda crappy, with the high revving and the awesome handling it's quite a fun car. It's just too bad that I moved to Chicago from California, as the roads here are utterly boring. Beside that, I'm planning to swap the engine for one with VVL.... so I'm okay with that. I just want to be safe as I depend on my car quite a bit.

Thank you.

eloplayspolo

Why does nissans entry level economy car have a better alternator than its higher end infinity line...?

DemonAstroth

Because mine is a 1995 model vs. the Sentra's 2001-2005 (B15) model.

I suppose the year made the difference.

GLN305

rskarvan wrote: »

GLN305,
This is entirely untrue. The alternator rectifier bridge monitors the system voltage. When the battery voltage drops below a certain pre-determined level (when the car is running), the alternator kicks in and supplements the system with a higher voltage to charge the system. Once the system rises above a certain thresh-hold, the alternator cuts off the the supply and lets the system run.

A good analogy would be that your alternator works sort of like a thermostat. It turns on when the temp (volts) drops below a certain level and cuts out when the temp (volts) goes over a certain level.

The BATTERY is the reserve where the power is stored.

If you don't believe me, disconnect your alternator (remove the belt), and your car will still run for about an hour or two strictly off the battery reserves.

- Ron S.

PS I worked as an engineer for Delco Remy for 13 years. Delco Remy manufactured starters, alternators and batteries for General Motors. I've also driven a few vehicles at highway speeds without a working alternator.

Well, the reverse can also be said, you can start a car and take the alternator out of it and it will run. I have also ran a car for some time with just the battery after my alternator belt broke. I guess in reality we are both correct because if the alternator just keeps the battery at or above a certain voltage to charge it, and the overalll current draw causes voltage to drop low enough that the alternator has to charge by raising the voltage, then the alternator will be charging continuously and will be running anything attatched to the charging system. Just two different ways of looking at things I guess, in reality the charging system as a whole needs to be healthy.

P.S. I didn't think the rectifier bridge would monitor the voltage, since a rectifier esentially converts AC that the alternator produces. A voltage regulator would monitor the charging system voltage.

GLN305

DemonAstroth wrote: »

I do not believe the battery to be the problem. I can run the stereo off the battery for a long time with no problems. That is the reason why I went with a yellow top. The problem even started before I put in the yellow top, it had some walmart battery before.

If the alternator is not supplying enough power to power up the 2 amps plus the regular car functions, I don't see how upgrading the alternator would be a "band-aid" solution. Would I not be changing the "faulty" part?

It's really not that big of a problem, as soon as I rev all my instrumentation lights up just fine, and unless I want to go deaf the lights don't dim at all. I just want to take preventive measures before I have to fix it.

I don't care too much about the power issue. The car is one of the best handling cars, and it revs quite high (7500 redline)... so although the power stock (145hp) is kinda crappy, with the high revving and the awesome handling it's quite a fun car. It's just too bad that I moved to Chicago from California, as the roads here are utterly boring. Beside that, I'm planning to swap the engine for one with VVL.... so I'm okay with that. I just want to be safe as I depend on my car quite a bit.

Thank you.

My mention of a band-aid would be if you replace the alternator knowing that the battery is bad. If you have a know good battery then an upgraded alternator is a great idea.

BaggedLancer

Iraggi makes really nice stuff. Seen there products numerous times in car audio competitions, never heard a complaint from anyone about them.

My suggestion..."Go big or go home."

Get the biggest you can afford and should you decide to add more stereo stuff later, you'll be covered.

rskarvan

P.S. I didn't think the rectifier bridge would monitor the voltage, since a rectifier esentially converts AC that the alternator produces. A voltage regulator would monitor the charging system voltage.

GLN305,
Rectifier (diode bridge) & voltage regulator are all built into modern alternators. So, you are correct... they are just part of the same "circuit".

HiPerf360

When increasing the size of the alternator you must increase the size of the main charge wire from the alternator to the battery.