Whats the title? "Im the fastest of an arbitrarily grouped section of racers".
Though I can see the point, if it was truly a world champion, it would be any car on the given track, who can go fastest. 1/12 electric vs 1/8 gas, etc.
That said, there are clear distictions between 1/12 electric, 1/10 elec, 1.10 gas, 1/8 gas, etc. Not so much when you spec a motor.