Unstable Voltage

I have a 92 3000GT SL 5-Speed. I've noticed that whenever the RPMs are up (when in accelerating or in neutral) my voltage increases, my headlights get brighter, my AC runs higher, etc... I am aware that the alernator is turning faster and creating this increase. What's bothering me is, why do I get this better performance? Shouldn't my lights be as bright as they can be when I turn them on? and How can I stablize the voltage without buying a voltage stabilizer? I've tried that, and saw no difference. Any suggestions?

what kind of voltage reading is the alternator putting out?

All the 3S's i've owned have done that, even with new alternator/battery. I accepted it as normal.

It fluctuates from just under 12V up to as much as 14V.

in my experience its usually a early sign of the alternator or battery slowly getting weaker

but, it may very well be a normal thing also. i have to check, i dont pay much attention to that

Thanks, I just put in a new Optima. I'll get my alternator checked.

If you have an underdrive pully this is normal, if not your alternator may be on the way out, but it may last years in its current condition. 12-14v is normal, under 12 is a little low, but mine used to do the same thing.