OP: There's different classes for drag racing:
Street:
Classic muscle
Modern muscle
European Sports
Euro lightweights
4WD rally
4WD race
Japanese tuner
FF
Racecar:
LeMans
Race-modded
Formula
Classic Racecar
X1
Racing one class vs another is pointless because each has advantages and disadvantages against one another. A 400hp 4WD will beat a 400hp FF or FR 90% of the time because of the lack of wheel-spin.
Example: My TommyKaira ZZ-II, with 740hp, will keep up with the 1k HP Dodge Viper up to 160-170, where the Viper's horsepower will overwhelm the weaker car. But if your racetrack is only 1/4 mile, the ZZ-II will win.
This is why I wish PD would set up a legitimate drag racing mode with classes and brackets for official drag racing.