Here's a 1:29 lap around Grattan. This was from an OTD in summer of 2021. My PB on this track is a 1:28.6 set the same day. Grattan is my absolute favorite out of all the tracks I've been on. Its said that the course designer was a psychopath for making such a wild layout for full power cars, and I tend to agree. This track has blind uphill corners, very tight twisties, long high speed sweepers, and "the jump" which rewards the bravest drivers with 4-wheel-off hang time. Its just an absolute thrill ride that despite having some level of danger, doesn't come off that way.
Car:
2020 Camaro SS 1LE
Stock Goodyear Supercar 3 tires
LT2 Intake
Rotofab CAI
Powerstop Track Day pads
GMPP strut tower brace