Re:engine noise at high RPM
 

uhm.. lets see... Engine spins faster as RPM rise (duh). Crank pulley is attached to the engine, so it spins at the same speed as the engine. Attached to that spinning crank pulley is a couple of belts (model dependant). Those belts spin on the crank pulley. At the other end of that belt is another pulley. It is attached to the alternator. So, when its all connected, the faster the engine spins the faster the alternator spins.... got it now ;) ?

Re:engine noise at high RPM
 

thanx, but i already understand how most of that stuff works. I just didn't think that when the alternator pulley was spinning faster it necessarily means that the alternator is "working harder." It may be spinning faster, but I didn't quite think that was the same thing. If the battery needs to be charged, I figured the alternator would work just as hard no matter what the engine speed.

Oh and thanx for the detailed explanation, Teal Terror, that's just the kind of tech info I was looking for. Now I can go impress all my friends, and be the coolest kid in school!

Re:engine noise at high RPM
 

im not givig you ----, when your battery is low, alternators will whine, and whine louder at high rpm. it does it on my crx if i leave the lights on, and i put a alt in my friends ram/charger and it whines all the time :)