I usually never see less than 13.5v in a log during a WOT pull, and 13.9-14.1v at idle. Perhaps cleaning up the current grounds, and perhaps even add a few more may help bring up that voltage. I know if my voltage was that low I wouldn't be doing any spirited driving until my issue was resolved. I'm so paranoid when it comes to voltage, that I have the factory boost gauge set to monitor battery voltage.