Have you put the new tires on the car yet? I'm curious to see how they compare looks wise to the Kumhos. I've got the 305/30 Kumhos now and am looking for something a little taller. So I've been looking at the 295/35 Yokohamas.
Yep makes me regret the 15. I heard complaints about 18 and up struggling to find a good gear on road course. But I didn't think about it the other way with autocross. Constantly running out of gear in 2nd.
I'm guessing gt350 trans has different ratios. I know I've got the shortest ratios possible, 15 and performance pack. Maybe the ol GoPro speedo isn't the most accurate 🤷🏻♂️
How the heck are you hitting 64 in second? My 15 with 305/30/19's is limited to 55. Did you raise the limiter or something? Also are you running any power adders?