I say this as basic rules for touge/time attack. We can do two classes, Class A and Class B, with maybe a third class as being "Unlimited", now hear me out.
Class A:
404hp max, Comfort Soft max, 1150kg weight max/min, or maybe we can do without the weight. These would be your normal "streetish" touge cars.
Class B:
650hp max, Sports Soft max, 1025kg min/max weight. Again, we could do without the weight restrictions and/or discuss. These would be your tuned up touge machines, or well built time attack cars.
Unlimited:
No horsepower cap, Racing Softs, no weight cap. JGTC cars, race cars, supercars would all fall under here.
What do you guys think?
Edit: I guess you would switch Class A and Class B.