what exactly does "ping mean?

http://i.imgur.com/08fzX.jpg   She was in the black LP570 roadster on the right, and I drove the blue 997 turbo behind her.   ... sweet jesus does Porsche know how to make a fast car. It's actually the fastest 0-60 out of that entire line up ( you're missing the F430 and the R8 in the photo too ). As my mom put it after I passed her, I was " sucking the tail of the Ferrari ".   Seriously the boost was like a freaking on off switch in that thing. Passing the California on the outside of a hairpin

Includes gland nuts, 210 miles on them, pretty much new condition. Asking 225 shipped. These are stiffer than most people think, only selling them because im going d2 coilovers. Ill post pics if anyone wants.   Danny

Hope you have a good one!!   -Robert