Dexos2 is primary a Diesel spec but it can be used without issue in Gas engines, if you look these oils are much more shear stable non GF-5 oils. HTHS also is around 3.7 vs 3.0 on Dexos1 oils.
With the high temps seen I'd never run a Dexos1 oil at the track or if you do change it immediately after. Per warranty change it to Dexos2, also ideally put some break-in miles on the oil before the track.
Id inquire at the dealer for Dexos2 oil or order Online from an oil off the approved list.
http://www.centerforqa.com/dexos-brand2/