I built a field of Gr.3 cars (19), all tuned to 715pp (714.51-714.89) on RM. Downforce ALL set to minimum (350/500), 2855lbs min (some are naturally higher, some for pp purposes). No Turbo or SC upgrades, Trans auto set tp 300mph, toe and LSD (basic for my liking) only. Found custom styles for most, and some of my own.
Then took a C8 Corvette, built to 699.89pp on RH, Custom High wing, wide body, rear diffuser for max downforce (250/380). SC and racing exhaust, custom 6 speed Trans set to close the same top speed, but lacks acceleration on new tires in comparison.
477hp/3000lbs.
ALL CARS have RH, RM, RS, INT AND WET tires at their disposal. Run 1 hour races and shorter sprints of 15-20 laps at different tracks. Since the C8 has a smaller fuel cell, fuel set to 3 or 4, tires 11-12, boost off, all others set to Real. Pit strategy is key and interesting. Having a blast starting last and reversing the field for the next race.