It was done with a 2014 model in 7:19 but was corrected to a 7:18.xx as Nissan didn't have the track to itself and had to slow in a section to pass a car. the 2013 did it in 7:22 and the 2012 with 530hp did it in 7:24.
in the fall of 2007 they marketed the launch of the GTR as 7:38 ( a few damp areas on the track) that car was the US 2009 sold in 2008. later in the spring of the following year they got that down to a 7:29 before the car was on sale in the US more than 10 secs faster than the first official time.
when the UK got the car as a 2009 it was the US 2010 that had 5 more hp and some other minor tweaks. Nissan using a stock car but with SpecV wheels ran the 7:26.7