Grant. I have AIM plots of my car against PDK same course with a driving buddy I spend lots of time with and are fairly similarly matched in pace. PDK pulls 1.2s a lap at this course. Manual looses three upshifts on the back straight which alone leads to a 7-9kmph deficeit at the end of the back straight (we both brake within 10m of each other). The 991.2 GT3 manual box is not long like the GT4 so on this track I need 5th gear in the GT3 vs GT4. We have also found that with the 991.2 GT3 the shift times are slightly slower than with the GT4. The power shifting option on the GT3 is no quicker than the rev hold option on upshift (sport mode) in the GT4. On the ring I think the extra power to teh wheels of the manual will offsset some of this but its lost on a short tight course. Randy and Water can shift quicker than I can but comparing traces between my GT3.1 and GT4 the manual 991.2 GT3 is loosing some time per lap as manual. I swapped cars with my buddy just to get his thoughts and he was adamant it was more time lost than his GT4 also (he now has GT3 PDK). Theres also much more doing on when trail braking and shifting down two gears with one hand on the wheel at the end of a 230kmph straight into a 80kmph corner - its much more difficult to modulate trail braking in the manual whith both hands on teh wheel etc. these are my real life experiences with Aim data and teh cars at same tracks. I had my cars standard with only small change in ge0 (same for each car - max out factory settings for negative camber up front and match at rear etc). My 991.2 GT3 has PCCB but other than that no diffferences. 

I will caveat by saving I am assuming they will put the GT3 PDK style box in with lightening shifts and no 7th gear as an overide... 


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2017 991.2 GT3 Manual, 2017 Alfa Romeo Giulia QV, 2017 Macan S (Petrol)