Alternator question

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swalve

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I have a 1997 Grand Prix GTP. The alternator is going out- bearings are getting loud. I want to replace it with a higher capacity unit.

I *could* buy one of those fancy reengineered units for $300, but I don't really need all that power. I'd just like to up it a notch for a little better power at idle.

I thought for sure I'd simply be able to find a GM oem part for an upgraded option, but after hours of internet searching, I couldn't find anything. They are all 105 amp.

But I did find a number of other vehicles that use the same 3800 engine that DO have a 140 amp alternator. Namely, the TransPort and the Bonneville SSEi. The Bonneville one seems perfect, as it used the same SC engine. However, the pictures look way different.

Does anyone know:

1- If it will fit?
2- Or, where can I find a cross reference for these parts? Somewhere, there has to be a chart that lists the specifications of the individual parts- this mounting hole at that position, connectors, etc.

At some point, I'll go up to Autozone and just ask the guys to let me see a couple of the different alternatives and see for myself. But if some here knows already, I don't want to reinvent the wheel...

Thanks in advance!
 
Is that the CS130 on that thing? They're notorious for overheating the rear bearings. My mom's 93 Bonneville had that and I had one on an 80 Trans Am. There used to be a rear housing kit with larger cooling fins and a larger OD bearing called the Iceberg kit. It worked really well, just have to make sure it fits your car. I had to clearance the fins a little to fit the Bonnie.
 
I would go to an alternator rebuild shop and ask them. They may have one or could build you one. You may need to upgrade the output wiring of the alternator to handle more power. Not sure I would bother unless you are pulling a lot of power from it with accessories at idle.
 
When people get "high amp" alts for stereos etc they're rewound and sometimes have less amps at idle!! Kind of like having a lumpy camp move the powerband to higher RPM.

If heat is killing these things, limiting current when their built in fans are turning slowly sounds like a good idea to me... I would not try to get more.
 
If all you want is a little better power at idle, then get a larger pulley for the stock rated unit. The belt should not have to be changed, but maybe.
A larger alternator will not necessarily produce more power at idle, and may be less.
By all means, just get a larger pulley for the alternator! They change on demand, BTW.
 
Yeah TooManyWheels, that's the Iceberg kit.

I believe by installing a larger pulley, you'd slow the alternator down. I think you mean smaller.
 
Nearly all GM alternators are weak, I am not surprised this is happening to you.

In some cases, however, the OE just locates the alternator too closely to a heat source and that drastically shortens the life. Such is the case with many V6 FWD cars, and certain high performance RWD cars.

I'm wondering about this MSD product here: http://www.msdignition.com/info.aspx?taxid=301&taxid2=303

Are they durable or not? I never have seen somebody that has one installed.

I wonder if there is a Denso alternator that fits your car. The longest lasting alternators I have ever seen came from Denso.

Bosch claims to have re-engineered alternators for many applications: http://www.boschautoparts.com/Products/AlternatorsandStarters/HighOutputAlternators But I'm not so sure about Bosch. They make the worst windshield wipers I have ever installed.
 
Originally Posted By: TooManyWheels
Googling NYEngineer's Iceberg lead I found

http://www.highampalternators.com/gm38_conversion_cs144.htm.

This seems to answer the question of fitment.


Excellent! Thank you. I found that site in my searches, but never came across that specific page. That seems to suggest that indeed a cs144 from a Bonneville should work.

(Also, you can see what I mean about the prices.)

Originally Posted By: NYEngineer
Is that the CS130 on that thing? They're notorious for overheating the rear bearings. My mom's 93 Bonneville had that and I had one on an 80 Trans Am. There used to be a rear housing kit with larger cooling fins and a larger OD bearing called the Iceberg kit. It worked really well, just have to make sure it fits your car. I had to clearance the fins a little to fit the Bonnie.


It is. It does seem a little whimpy.

Originally Posted By: eljefino
When people get "high amp" alts for stereos etc they're rewound and sometimes have less amps at idle!! Kind of like having a lumpy camp move the powerband to higher RPM.

If heat is killing these things, limiting current when their built in fans are turning slowly sounds like a good idea to me... I would not try to get more.


My issue is, and really has always been, that the alt doesn't put out enough juice at idle. That's why I wanted to go with a factory type replacement like that cs144. My theory being that its "power curve" would be flatter, giving more power at idle. Using a smaller pulley would probably give me the idle power I want, but I fear that the higher speed of the rotating mass would slightly rob power. As it is, the alt turns at something like 3-4 times the speed of the crank? That's not so bad at idle, but at higher revvs, it seemed a little scary.

Just doing some ballpark math on it, lets say the factory setup is 4x. At 4000 RPM, the alt is turning at 16000 RPM. If I upped it to 5x, it's turning at 20000 RPM. That extra 4000 rpm you're spinning the alternator to every time you accelerate will, it seems to me, sap power. I tried to figure out how much, but I couldn't figure it out. Not much, but I'd like to avoid it if possible.

In a perfect world, I'd think that you'd want to have the alternator spin slower. But I suspect you'd need to increase the size of the alternator a LOT to be able to do that.

Originally Posted By: artificialist
Bosch claims to have re-engineered alternators for many applications: http://www.boschautoparts.com/Products/AlternatorsandStarters/HighOutputAlternators But I'm not so sure about Bosch. They make the worst windshield wipers I have ever installed.


I've had and heard of similar issues with Bosch.
 
Have you checked for voltage loss between the B+ on the alt and the battery? Sometimes the wiring is undersized or corroded and you end up losing some voltage that way.
 
I believe I have the CS144 on my 98 Yukon. The original one failed at 65,000 miles. I had a reputable old school shop rebuild it and it lasted to 200,000 miles. Actually, there was nothing wrong with it, I just figured why tempt fate, so I went to the same shop and got another one.
Way superior to the 130 in my opinion.
 
One of the main problem with the bonneville and Grand prix alternators up to '97, were that they were located directly above the exhaust manifold. You could try adding a heat shield, or even wrapping your factory manifold with header wrap. This will most likely prolong the life of whatever alternator you descide to you.

My folks had the same problem with their '94 Bonneville. Great car otherwise, and a great engine. It just didnt like its alternators very much!
 
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