caranddriver had the PP2 vs GT350 and even thought the pp2 stopped quicker and had more lateral grip (apparently the version of the tire on the PP2 has more grip and less longevity vs GT350 OEM tire) the stability and tuning of the suspension on the GT350 put it two seconds ahead at Grattan. On the same tires it may be 2.5 seconds. AutoX will be a shorter track and the power difference may not matter, but the 350 should still be a fair bit quicker around the course.It would have been interesting to see a GT PP2 and an EB performance pack car run as well same day same driver on this very small autocross course. I wouldn't be surprised if the GT PP2 is very close to the GT350 times on a tiny track like that. Heck, it might be faster than the GT350. I know the times I ran small courses with the GT350 I had to be gentle with the car and it was tough to use the power even of the GT350.
Hopefully before long we will see the GT500 on a larger course.