For slotting it's arguable that yes it matters. For cross drilling, not at all.
Whay is it that you think that cross drilled rotors have to go on in a particular direction. Use physics in you reasoning.
exactly, the veins have to run in the same direction as the drilling.the only thing that matters is the directions of the veins inside of the rotors, they'll pump the air effectively in one direction only depending on their design.
You see, at ulta super high speed teh rear wheels are actually turning..... backwards....
Stealthx32 is right. You need to look at the vanes. They may not even be directional, mosr cheap drilled/slotted rotors arn't.What? No it doesn't. You can't tell a thing about which way the vanes run by looking at the face of the rotor. You could drill it like a puzzle and it wouldn't matter (as long as it's balanced).