I don't think there is a thing as going "too fast" though safety and driver experience and mentality surely come to play. Who's to say where Top Fuel and Funny Car speeds would be if the NHRA was still running a 1/4 mile instead of 1000ft? I truly believe that one of the reasons Nostalgia racing is becoming so popular is because they travel the full 1/4 mile and aren't as fast or quick as their big brethren. It also helps that Funny Cars actually more closely resemble a make and model car.