Now I'm probably not the authority to be talking about Super GT, but 2'09 sounds a bit slow...
I know my Calsonic Skyline does around 2'00 on stock power, min downforce, and RS tires.
60hp is worth about 4.5s at Sarthe... so probably worth around 2.5-3.0s at Bathurst.
There's an 80hp difference between the two, so around 3.25s difference, perhaps?
Plus the RS ---> RH is around 5.0 seconds for Bathurst...
So...
2'00.000+3.250+5.000= 2'08.250
And this assumes the GT300s would even with my Calsonic Skyline at equal power, weight, downforce, balance, and tires. This is not close to the case. Super GT300s would be much faster than my crappy GT-R. Probably another second or so. Plus I'm horrifically slow in Super GTs, so take off another second.
That brings the time to 2'06.250.
I don't remember if that was ran with tire wear off, and even if so, it would take off another 1.5 seconds at MOST.
So 2'07.750 would probably be the pace speed.
Again, it has been a while since I've gotten on the game... almost a full month now... but something tells me 2'09 seems a bit slow.