I have talked to the guy at Big Brakes Australia, who is the person that designed the slotted and drilled rotor for DBA and he told me that the drilled holes basically will do fuk all and make the disc a little weaker- they r mainly there for looks.
Talk to the guys at Big Brakes Australia they were champions to do business with (rotors were personally delivered to my house when i couldnt pick them up b4 the weekend!!!! at no charge btw)
All the touring cars only have slots- non of there rotors r drilled so that sorta shows sunfin. If Dick Johnson
doesnt have drilled rotors why would i need em?