Off memory, the fastest US time in 2013 was a 17.3xx and I could have leapfrogged a ton of spots with an extra tenth or even less. Problem was trailbraking for that left in S1. I couldn't get that Z to do it at all while everyone else could.
Conversely, the GT3 GT-R was a dream machine. Given the final cut-off time for 2014, running it was so easy, I couldn't believe it.
Two things I must mention: the 2013 Academy was a free download since GT6 wasn't out yet. Therefore, there was more competition than 2014. Also, the handling dynamics in the time trials last year were noticably different than any public lobby or even offline. Only way I can describe it is that the GT3 in the game today is downgrading from a Mercedes F1 to a Williams.