Compared to last time (https://www.youtube.com/watch?v=p3sw7KPRqZU) it was a 0.5 second improvement. Changes of setup were:

1. the front sway bar was one slot softer (this helped a lot; in the previous run the car understeered a lot),
2. tires went from V730 to a set of old Bridgestone RE 71RS, 275 at the front and 295 at the rear, 
-- the tires were left on the shelf for a year but it held up great!)
-- meanwhile, this (https://www.youtube.com/watch?v=7vgcNtSWe10&t=8s) is when this set of tires were first used; it has interesting comparisons between before and after repavement, as well as with and without the Bimmerworld GT Swan Neck rear wing.
3. The set of GLOC R18 brake pads was done before this track day; I switched to a substitute that was more or less street oriented.