I've just noticed that my battery voltage is dropping to ~11.7 when I'm running through the 1/4 mile WOT. It's normal (~13.2) when cruising. New battery, pretty new alternator, tight belt. Any ideas?

Any symptoms?

I'd check to make sure the gauge is reading accurately.

It's definately low. My scanner is reading low and I just got my wide band O2 unit hooked up, which requires a constant 13V, and it's turning off when I go WOT.

Maybe the alt is spinning too fast? This happened it my pick up truck. If I revved it up too high the radio would shut off because of loss of power. Just a thought.