most will only put out their ratings at 1000-1500 rpms. at idle, they put out around what the stock alternator was. there are some that put out more at idle or as Dane said, you can sometimes get them built that way by request.
my iraggi puts out 110 at idle and 200 at 1000rpms
Excessive amperage alts dont all put out 200amps at idle, only his large case alts put out that kind of power at idle..an i just bought a 300amp alt from him an the print out he send said that his alts kick on at 800rpm's but his website says they kick on when the car starts so i dont know an the paper also says full output at 2200rpm an on the website it says full output at 1200rpm so i really dont know about this but i do know that it also says his large cases kick on at 650rpm an then put out 100amps or more
the alt is kicking in at idle tho an it seems to be doing a tad bit more then my stock was at idle an when driven about 25mph it stays at 13.8 volts with my stereo turned up to about 55 ( which is the loudest i usually leave it at for long periods of time just because any louder an it kills me ) so its working out ok
yes it's normal. that's why most alternators are rated "above idle." the output is based on how fast the alternator is turning, and that changes with engine RPM.
so if that's the case Glass, if you just got ahold of a stock alternator and you wanted to increase its output, simply swap the pully to a smaller one? They don't require any beefier internal mods??
matt you can ad a smaller pulley yes, but that doesn't add much in most cases. the beefed up internals help more when an alternator is rewound with more turns, and larger diodes. you also have to consider ventilation and heat issues with the casing.
Mitch, you can install a voltmeter. radio shack even carries them.
