The Biggest Alternator

[ZZ]

What is the largest alternator (amps) I can get for my '90 GMC 6.2?

It has what I call the smaller 1 wire unit on a serpentine belt. Do they make a 200 amp version?

[NH2112]

What do you plan on pumping 2400 watts into? Even a weak battery charging at its max rate won't pull more than 30A, and that's for a short time only. Will your wiring be able to handle 200A of current without ending up resembling the filament in an incandescent light bulb? I personally can't think of any truck accessories that would require anywhere near 2400W, not to mention that as a general rule the higher the peak amp output is, the lower the output at idle is. At idle a 200A alternator will probably barely be able to power the headlights and defroster.

[ZZ]

I'm running a Rockford Fosgate 800 watt amp and the voltage drops significantly at idle at night at traffic lights. I just need something to handle it better.

[Dieselboy]

I have a Powermaster small case rated at 140 amps, but it actually turns out 160 at 2000 shaft rpm. At idle, it does 90 amps.

It's worked well, and for $150 it was a nice bang/buck. But be prepared to replace you v-belts with regularity. The groove on the pulley is made to get extra grip at the cost of belt life. I change belts at 6 month intervals while driving about 10,000 miles/year.

[NH2112]

Best thing to do, IMO, is take yours to a good shop and have it rewound to put out a higher percentage of its peak output at idle.

[ZZ]

I have a chrome 140 amp now that I bought on EBay. I just thought there might be a bigger one that would put a lot at idle & town driving speeds.

Thanks for the responses.

[84 Convert]

Do you know if the pulley size is different than the one it replaced? If you were to use a smaller pulley, it might make it spin fast enough to do what you want it to at idle. It is pobably one built with a gasser in mind, and since these diesels don't spin up as far as gassers, you have less chance of overrevving it.
Of course, if you must have amps, Mean Green makes some that top 240 amps for around $360. You can also check with companies like Premier Power Welder and others who make underhood welder systems. They will usually sell you only the alternator if that is what you want.
Just a thought.

Gregg

[ZZ]

Thanks, I'll check into these.

[ZZ]

I'd forgot about this thread. My problem has worsened since I'm running the A/C now.

The chrome alternator that I put on does have a smaller pulley than the stock had. I don't think I could go much smaller.

[crew84]

Forget about using a smaller pulley. A V-belt pulley with a large amp output generator would need more surface area on the pulley for the belt to hold onto to prevent slippage. Once it starts slipping the belt is useless. I believe that the same would be true for the serpentine belt.

[ZZ]

Thanks, that makes good sense. I'm about ready to get a smaller amp and not have this worry.

[befland]

As usual, Dieselboy hit the nail on the head. You can get some really high output alternators but they put out practically nothing at the RPM's that our trucks idle at. I bought a powermaster that had been specially wound to output over 100 amps at idle. I have yet to install it because I plan on converting my multi belt system to the serpentine setup...so I don't know if I got a lemon or not. I have a 90 amp installed currently and at idle my lights dim. You can even see the voltmeter gauge move to the other side of 12V. I'm sure it is not wound for a diesel.

[doncannon]

Ok once I had a cavalier (I know just hear me out) and I installed driving lights (hi watts). They would also drain the system at idle until I got a set of lights that had a relay, then they worked fine.
I was just pondering. Maybe someone else has an idea or the place were you got the amp could have suggestion. I like big things (horsepower, tires, and yes big amps) Good luck and keep us posted how you make out!
Don
I would like to put a good stereo amp and speakers in my ride too!

[Lothar]

Buy 2 optima yellow top 900 CCA batteries.

If only i could keep my truck from overheating!!! :mad:

[ZZ]

I sold the 800 watt Rockford Fosgate amp, and my g/f is going to get one that is 200 watt for my b-day next month.