It’s going to be the same as the Infiniti G37, which run 13.9-14.0 @ 100-101. I dunno where you got mid 13’s @ 103-105 for the 350Z. They run high 13’s bone stock, like 13.7-13.9 @ 100-102. 6 spd’s with headers, Borla duals, CAI, & a high flow cat are running 13.4’s-13.5’s @ 103-104. Supercharged 350Z’s and a few nitrous 350Z’s are running low low 13’s and dipping to 12’s with like 12.9’s-13.1’s @ 106-108.
I was a little bit low for the averages, but bone stock 07+'s are running low 13’s. Not every time, but they are doing it http://my350z.com/forum/3035974-post7.html .
S/C Z’s are running considerable quicker than 12.9’s, too and and 12 out of the top 02 trapped above 110 with 3 or 4 113’s in there. http://my350z.com/forum/3035890-post3.html