Actually you will know if you've gone too far on the limiter if the car seems to sputter at steady state speeds. So as you follow TOHCan's recommendation, just keep uping it until that happens. If the pinging during throttle tip in starts to come back before you reach this point, then adjust with the allen wrench.

You should be able to walk it in pretty quickly, so why wait? And since you already have the values don't worry about "screwing it up" you know how to get back to the original settings. Tuning is fun! (When it goes smoothly)