Originally Posted by sqela
on the track what is the advantage with the drilled rotors. (decreased weight?)
Decreased weight is a minor effect, drilling is primarily for cooling. But extreme heat up and cooldown cycles shorten the life. They're designed to last for one race and then toss them.
Ever seen the under-car cameras during a NASCAR race? Particularly on the short tracks like Martinsville and Bristol? It'* spooky.
The rotors get RED hot twice per lap. Over and over again. They explode when they get too hot.
Paul'* reply above is right on the money. If it'* done RIGHT it can be safe for street use. But the vast majority are not RIGHT for street use. If you can afford them, they're bad.