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1991 Loyale Alternator Question (car audio)


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I installed my sub and amp (500 watt RMS) into this 91 Loyale that I just inherited from my Dad. The sub and amp was previously in an 02 Buick Regal, and worked perfect.

 

When the Loyale hits higher RPM (about 2500), the voltage gauge goes up, near 16 or 17 volts, and the amp turns off. Once the RPMs go back down after I shift, the amp turns back on.

 

Can an alternator provide too much voltage? I thought the voltage was regulated but maybe it's not. The lights don't flicker or get dim when the sub hits, so there's plenty of amps.

 

Is there maybe a way to mod the alternator in some way to make it put out a constant voltage?

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I installed my sub and amp (500 watt RMS) into this 91 Loyale that I just inherited from my Dad. The sub and amp was previously in an 02 Buick Regal, and worked perfect.

 

When the Loyale hits higher RPM (about 2500), the voltage gauge goes up, near 16 or 17 volts, and the amp turns off. Once the RPMs go back down after I shift, the amp turns back on.

 

Can an alternator provide too much voltage? I thought the voltage was regulated but maybe it's not. The lights don't flicker or get dim when the sub hits, so there's plenty of amps.

 

Is there maybe a way to mod the alternator in some way to make it put out a constant voltage?

 

it sounds like the voltage regulator is going bad. it is internally regulated and you will likely have to replace the alternator.

lots of amplifiers have an over-voltage protection circuit built in, likely it isn't hurting it but is certainly annoying.

 

Ben

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Replacing the alternator is easy. Its right on top of the engine and easy to get at. I got a new one for $120 CAD after the core return. Or you could try fixing the alternator. Machine the stator, new brushes and new regulator but the parts are hard to find generally.

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and please bear in mind that these are only 60 amp alternators - adding aftermarket high wattage items like amps, driving lights, etc will kill them quickly.

 

There is an "upgrade" out there for using a 100amp alt from another vehicle, but requires a little more work - do a search for the info.

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and please bear in mind that these are only 60 amp alternators - adding aftermarket high wattage items like amps, driving lights, etc will kill them quickly.

 

There is an "upgrade" out there for using a 100amp alt from another vehicle, but requires a little more work - do a search for the info.

If I remember correctly, the XT6 alternator is a drop in replacement and rated at 90 amps. GD has numerous posts about installing a 100 amp version.

 

As to the high wattage of the amp, 500 watts is only a little over 40 amps draw (divide 500 by 12). During the daytime, that should work okay; but at night when your headlights are on, you'd be overloading the existing alternator.

 

And to the original question, the internal voltage regulator is bad. That normally requires replacing the bad alternator. From the tone of your response, you'd be better off replacing the alternator (easy job) than trying to rebuild the one you have.

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An XT6 alternator? Is that a type of alternator, or is that a different Subaru? What year XT6 do I look for to find that alternator?

 

An XT6 is a different Subaru, a little 2dr coupe.

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I would suggest (like the others) you just replace your alternator. Dont rebuild the current one, and if you plan to run subs and an amp, it will destroy the alternator at night, or even during the day time if you run with headlights on. Therefore I would go with the Nissan Maxima alternator swap - GD has the write-up, let me see if I can find it...

 

Here is Rick's (GeneralDisorder) write-up on the Nissan alternator (90 amp)

http://www.ultimatesubaru.org/forum/showthread.php?t=100559

 

You can contact Rick as well to get anything covered that he hasnt mentioned, but it seems pretty straight forward...

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I wouldn't mind doing a slight mod of an alternator, but without a grinder, it looks like I can't use the Maxima alternator. I'm going to look for a direct replacement and hope I find one that had high amps. If I can only score a 60 amp, then I'll just keep the sub turned down.

 

Thank you all for the helpful tips

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Where are you located exactly?

 

I believe GD was selling one and said he'd make them for people, would be worth asking him...

 

The other thing is to ask someone near you to either let you use their grinder/belt sander or see if they will grind it down for you...

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  • 3 weeks later...
  • 2 weeks later...

Keep in mind that you will never be using the full watts or amperage that your amplifier is rated for. I have a 400 watt alpine amplifier powering my 10" kicker cvr. Playing a loud, bassheavy song I can only draw about 8 amps (measuring my positive wire from my battery to my amplifier.) this means I'm getting about 108 watts to my subwoofer, which in this case means about 106 decibels.

Someone correct me if I'm wrong, I've been doing quite a bit of research lately regarding this subject.

Brian

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Sorry for the double post, but I realized that I forgot to factor in amplifier efficiency. The alpine amplifier I mentioned before is a class d, which is around 80% efficient. That means that 20% of that current drawn from your battery/alternator is lost in the form of heat.

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Keep in mind that you will never be using the full watts or amperage that your amplifier is rated for. I have a 400 watt alpine amplifier powering my 10" kicker cvr. Playing a loud, bassheavy song I can only draw about 8 amps (measuring my positive wire from my battery to my amplifier.) this means I'm getting about 108 watts to my subwoofer, which in this case means about 106 decibels.

Someone correct me if I'm wrong, I've been doing quite a bit of research lately regarding this subject.

Brian

 

Sorry for the double post, but I realized that I forgot to factor in amplifier efficiency. The alpine amplifier I mentioned before is a class d, which is around 80% efficient. That means that 20% of that current drawn from your battery/alternator is lost in the form of heat.

 

the stock system is designed specifically around the car's stock requirements - anything above and beyond the STOCK items WILL kill the alternator more quickly - this is a proven fact via life experience for me.

 

I had a cheap after market stereo (nothing fancy, no amps, kickers, etc) and a set of 100w driving/fog lights installed on my old GL wagon - that car was eating alternators at the rate of about 1 per year if i used the driving/fog lights on a regular basis(thank goodness for "lifetime" warranty)

if I did not use the lights unless absolutely neccessary, it would last longer (keep in mind i had this car for about 8 yrs - lots of time to experiment)

 

when you take your measurements - how about doing it with the car running, headlights on, heater/ac on, windshield wipers on, rear defrost on, and any other "accessories" that you may have that you run frequently, and your stereo equipment ....because that would be more "real world" than measuring JUST the stereo equipment by itself.

Take a look at the load you are putting on your charging system then.... :rolleyes:

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You have to consider that the stock 55 Amp alternator only puts out about 20 to 25 amps at idle. If you are pulling 8 of that for your stereo amp.... not much is left for the rest of the car.

 

Alternators (generators and motors in general) are stupid - REALLY stupid. They will attempt to give you whatever you ask of them. If you ask for 70 amps from a 55 amp alternator - it will do it for a short time (till something overheats and gives up) because there is no fail-safe system in place to prevent it from doing so. Electric motors act similarly - if you ask for 10 HP from a 5 HP motor..... it will try very hard to give you this. In fact it will probably catch fire and burn itself down trying! Not funny - I've seen 4 foot flames shoot out the rump roast end of some rather large electric motors being over-amped.

 

In addition to that, the Amperage "rating" of an alternator is at cruise RPM. Usually 3600 RPM for the alternator which is around 1500 RPM for the car's engine. If it's idling at 700 you have to derate it accordingly.

 

The battery acts as a buffer and will supply some of these amps - but the battery is a double-edged sword because due to it's nature as an electrical "sink" it will drink as many amps from the alternator as the poor thing can make if it's drained. That's why you never hookup a new alternator to a car with a dead battery and then just jump it and go. The battery will take everything it can from the alt and drive it at max capacity - which they are not rated to produce for any reasonable length of time. A 55 amp alt will not survive long if you ask it for 55 amps all the time. They simply arent rated for 100% duty cycle.

 

GD

Edited by GeneralDisorder
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Very nice explanation GD! There is another option in using the GM alt.. It is rediculously easy and probably less time consuming than the Nissan but if Rick is doing them spend the money and get it done. BTW the GM alt really needs a different pully on it. At an idle everything dims even without the stereo on. @ cruise It never had power problems and was running close to 1500 watts of stereo constantly.. OK not really but I have been known to crank it for somewhat extended periods.. With that much power the extra 10 amps helps a lot. I have both and like each for what they are. For a daily without too many goodies I would go Nissan for major power suckers I would use the GM.

 

Mike

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Keep in mind that you will never be using the full watts or amperage that your amplifier is rated for. I have a 400 watt alpine amplifier powering my 10" kicker cvr. Playing a loud, bassheavy song I can only draw about 8 amps (measuring my positive wire from my battery to my amplifier.) this means I'm getting about 108 watts to my subwoofer, which in this case means about 106 decibels.

Someone correct me if I'm wrong, I've been doing quite a bit of research lately regarding this subject.

Brian

 

Some of this info is somewhat wrong and depends on the brand/setup. I have 3 amps that I own right now that put out about 100watts MORE than they are rated for, and yes I have tested all 3 of them. This is not uncommon among the higher end/more expensive brands. So this all depends on the amps, your power wire, and all sorts of other things that are going on in your install.

 

I can tell you right now that I pull about 80amps alone for my stereo I have in my car now. Yes, that's 800watts RMS when at full bore without any clipping. 510watts (37v AC@2ohms) to the sub, the rest to the front speakers. And this is from the speaker terminals on the amp, AFTER taking into account amplifier efficiency/inefficiency. (Oh, and my sub amp is rated at 400 watts RMS, not 500watts, and it never shuts off due to heat, and I have been running it this way for over a year now...) There's pics of my old install around here somewhere where I had all this installed into my loyale if you care.

 

It's easy to calculate this if you have a DMM handy. Well at least you can get close to it. If you really want to tune your system right, you need a o'scope and a 50hz test tone to play, and then you can see the wave form of the sound wave playing and adjust your gains to the max with out clipping the sound wave. If you want more info on this, PM me. I got a bunch of info and sites for you to check out if you really want to know more of the theory behind it all this 12v stuff. I nerded out on stereo stuff about a year ago, and learned a TON. I also only run high end stereo stuff, so that makes a difference as well.

 

So I did the maxima alt upgrade when my stereo killed my alt about 2 weeks after installing my stereo :lol:, and it was a HUGE improvement overall, and I would recommend everyone do it when the stock alt dies, even if you don't have a single extra accessory wired up in your car. I also had some hella offroad lights that I ran all the time, and they pulled about 10amps additional all the time, so adding that extra 35amps from the maxima alt made a world of difference. No more lights dimming at a stop light, no more dim lights with the stereo was cranked, it was awesome. I could idle my car with lights on and heat full bore, and the voltage would be at 13.9v. There is no way the stock alt can do that. I really don't know why subaru put such a small alt into this car. The stock alt can't even keep up with the stock accessories :rolleyes: I would highly recommend this upgrade to everyone!

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Some of this info is somewhat wrong and depends on the brand/setup. I have 3 amps that I own right now that put out about 100watts MORE than they are rated for, and yes I have tested all 3 of them. This is not uncommon among the higher end/more expensive brands. So this all depends on the amps, your power wire, and all sorts of other things that are going on in your install.

 

I can tell you right now that I pull about 80amps alone for my stereo I have in my car now. Yes, that's 800watts RMS when at full bore without any clipping. 510watts (37v AC@2ohms) to the sub, the rest to the front speakers. And this is from the speaker terminals on the amp, AFTER taking into account amplifier efficiency/inefficiency. (Oh, and my sub amp is rated at 400 watts RMS, not 500watts, and it never shuts off due to heat, and I have been running it this way for over a year now...) There's pics of my old install around here somewhere where I had all this installed into my loyale if you care.

 

It's easy to calculate this if you have a DMM handy. Well at least you can get close to it. If you really want to tune your system right, you need a o'scope and a 50hz test tone to play, and then you can see the wave form of the sound wave playing and adjust your gains to the max with out clipping the sound wave. If you want more info on this, PM me. I got a bunch of info and sites for you to check out if you really want to know more of the theory behind it all this 12v stuff. I nerded out on stereo stuff about a year ago, and learned a TON. I also only run high end stereo stuff, so that makes a difference as well.

 

So I did the maxima alt upgrade when my stereo killed my alt about 2 weeks after installing my stereo :lol:, and it was a HUGE improvement overall, and I would recommend everyone do it when the stock alt dies, even if you don't have a single extra accessory wired up in your car. I also had some hella offroad lights that I ran all the time, and they pulled about 10amps additional all the time, so adding that extra 35amps from the maxima alt made a world of difference. No more lights dimming at a stop light, no more dim lights with the stereo was cranked, it was awesome. I could idle my car with lights on and heat full bore, and the voltage would be at 13.9v. There is no way the stock alt can do that. I really don't know why subaru put such a small alt into this car. The stock alt can't even keep up with the stock accessories :rolleyes: I would highly recommend this upgrade to everyone!

 

My apologies, I should have been more clear. It is not often that you will be using your amplifier or speakers to their full potential, especially at just "cruising" volumes. It's not really that hard for any brand amplifier to pull big number amps like that or produce high number watts... Actually turning your volume up enough to consume all of those 800 watts is pretty substantial.

 

Your subwoofer would be fine with 500 watts RMS going to it even though its rated at 400 watts RMS. For one, most manufactures (Kicker, Rockford Fosgate, and JL Audio especially) underrate their subwoofers. For two, I really doubt that you are actually ever cranking the volume up to consume all of those 400 watts RMS.

 

Thanks for the info on the alternator! If mine ever goes out, thats what I'll be upgrading to for sure. Did you junkyard yours?

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My apologies, I should have been more clear. It is not often that you will be using your amplifier or speakers to their full potential, especially at just "cruising" volumes. It's not really that hard for any brand amplifier to pull big number amps like that or produce high number watts... Actually turning your volume up enough to consume all of those 800 watts is pretty substantial.

 

Your subwoofer would be fine with 500 watts RMS going to it even though its rated at 400 watts RMS. For one, most manufactures (Kicker, Rockford Fosgate, and JL Audio especially) underrate their subwoofers. For two, I really doubt that you are actually ever cranking the volume up to consume all of those 400 watts RMS.

 

Thanks for the info on the alternator! If mine ever goes out, thats what I'll be upgrading to for sure. Did you junkyard yours?

 

For the record I am only responding because my response has everything to do with why I did the upgrade for the alt for begin with, not to be an a$$hat or anything :)

 

I think there are a couple of things you missed in my post that you really should pay attention to if you are really interested in learning about car audio. There is alot of math and theory behind it all, I didn't just make all this up.

 

You are correct in saying that any amp can put out big numbers, but not without clipping. Clipping kills amps and speakers and this is what separates the men from the boys if you would when dealing with amplifiers and manufactures. You really need to understand this concept if you really want to get into loud, clear car audio. This is also why adjusting your gains correctly can make or break an install, is one of the biggest reason why younger kids will "blow" their equipment, and it can make the difference between the install sound like crap and it sounding fantastic. It's because if the gains are adjusted wrong and it sends the amp into clipping, which will eventually destroy the amp and/or the speakers, and all the while making the audio sound like crap.

 

All of my amps are adjusted to not clip at 75% of my headunits volume (on number 24 out of 32) and be amplifying the signal to it's fullest potential (deemed by me, not the amps ratings) at which time my system will be putting out 800 watts. This is not by accident, this is a number I came up with when trying to figure out how to adjust my gains on my amps. My system is actually rated at about 1000watts RMS and can put that out, but I don't run it at that because it's just too loud and puts too much strain on an already taxed electrical system.

 

I should also mention that I am into SQ, not SPL, so even though it gets loud, it still sounds really good. That was the entire point of my install, not loudness, but sound quality.

 

A little side note... If you look at the fuses on the amplifier itself and multiply that by 100, you will generally get what the amp is capable of without clipping. One of my amps is fused for 60amps, the other one 50amps, hence about 1000 watts RMS give or take a little. Same concept can be applied to offroad lights and the like as well.

 

Coming from someone who spent lots of money ofnall of his stereo stuff, I can tell you that I for sure use all of that 800 watts almost daily. I didn't spend the money on this stuff to not use it :D I generally drive around with my stereo between 18-22, and when a good song comes on it goes all the way up to 28. I designed the system so that when I drive down the freeway with all my windows rolled down @70 mph, I still have to turn the music down because it's too loud :grin: Granted I don't listen to it THAT loud all the time, but a majority of the time I am using well over 60% of my systems capacity. And this is all without clipping or any distortion what so ever from any of my speakers. I also bought all my equipment with this in mind as well. My sub can handle up to 650 watts RMS, and my front components 150 watts RMS. Again, I am not pushing the system to its limits because there is no need to, it gets plenty loud and sounds plenty good without the need of stressing my car or my equipment.

 

This is also why my alt failed in my loyale within 2 weeks of installing my stereo, it was just too much stereo for the little, old alt. I tried to avoid this a little bit when designing my install, but when there just isn't enough power there from the alt, but the little alt is trying as hard as it could like GD suggested, it really didn't stand a chance. I knew this, and had a backup plan in the works already before it failed.

 

What's my point in all of this? You would be surprised at how much juice a decent, not a huge, but a decent stereo will pull. I could see easily pulling 20-30 amps off of a "normal" stereo install with a couple amps and a sub. Hell, even 3 sets of hella offroad lights (about 30amps) and you would be maxing out the alt. Thats why the maxima alt made a world of difference.

 

That's also why my 70amp alt in my legacy is still working today and stands a fighting chance even with the same system installed from my loyale. That extra 15amps makes a difference. When it fails, I am going to be upgrading it to the 90amp version found in the newer legacy's for the same reasons I listed above.

 

Now did I junkyard it? The first alt I got, I got from GD. He went to the yard, got the alt, tested it, made the spacer for the pulley, installed the pulley, and sent me the whole alt as a package that was ready to be installed (mostly, still needed to do a very small amount of "wiring" on my end, especially because of my turbo). I would highly recommend getting it through GD if you don't have access to a lathe, and he is a good guy to boot. But it failed, and GD took it back and essentially gave me my money back. So then I got a reman Bosch alt, and it failed within a month as well. So I think there was something up with my loyales charging system, but I totaled it before I could figure it out. So I would grab a junkyard alt and give it a go. If it fails, you are only out a little bit of money. It's a lot cheaper to go that route than the $130 I paid for the bosch unit.

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