Amp rating on alternator?

[GNBRETT]

I see high performance alternators ranging from 50-220+ amps. I was looking at a couple of alternators but they are rated at 100 amps or so. How important is it to buy an alternator with high amps?

I see Race Proven alternators RaceProven.com: Alternators: Racing range from 50-200 amps. I am looking to buy one of these possibly and was wondering what was the smallest amp I could buy to work on my street car. They get pricey as they go up in amps, they are pricey to begin with but I was thinking the 160 would work fine but the 110 would be better. This all assuming ones not running big subs/amps, etc....

Any advice?

 

[BlackBandit]

Buick saw fit to put a 120 amp alt for stock applications. I wouldn't go below that unless you're running less electronics than stock or a trade off like no a/c and heat (blower motor) but a bigger fuel pump and even then I'd be weary. Any additional motors like radiator fans and fuel pumps put allot of load on the electrical system. I guess if want a reccomendation I'd say go as big as you can and only drop down to a 120 on a stock gn you don't plan on modding. If you put a alt that's not designed to keep up with your needs on the car you're just asking to replace it. You might look into a kit to upgrade your stocker to a 200 amp unit. hth. james

 

[GNBRETT]

Yea, I was thinking that I should not go below 120 but are some of these higher end alternators rated on the same scale as a stock alternator would?

I was also looking to buy another March Performance billet alternator (Had one on my old car) but it is rated at only 100 amps. It's a very nice piece and not cheap either so I find it hard to believe that a stock alternator would perform better then it would. Would it? I really don't know im asking?

 

[mikestertwo]

The stock 120 amp alternator works just fine. Unless your running big stereo power amps or other high current electronics I wouldn't waste my money. JMHO.

 

[BlackBandit]

I find it hard to believe that a stock alternator would perform better then it would. Would it? I really don't know im asking?

Don't under estimate the quality of gm's stuff. March has to satisfy a few thousand (maybe) people a year and has the luxury of saying "you over loaded this unit" or "this was on a modified system so it's not warranted. Gm has to put out a unit that works or else pretty much.