Rotor Orientation

[StickMon]

This doesn't look right.
Actually, it does look right, but it's marked left.
Rears are marked the same.

[inTgr8r]

Yes they are correct.
It's related to air flow through the internal vanes, not the look of the holes & slots

[StickMon]

Thanks inTgr8r!!

Upon inspection of the internal "impeller" slots, they are in the same orientation as the rotors on the car.
In a "throw out" rather than a "scoop in" in the direction of travel.
It's just the cross drill pattern and slots that are reversed from everything I've seen.

[Gallardo Rosso]

You always want the "throw out". Rotor vanes are designed to be centripetal pumps using rotational speed to eject the fluid. Putting the scoops forward would still make the air eject radially, but the flow will drop significantly... Typically 40-60% less flow. It isn't necessarily intuitive so be careful.

[StickMon]

Thanks. Makes perfect sense when you put it that way.

I wonder what ECS thinks they have going by orienting the holes and slots opposite to everyone else.

[The HACK]

The positions of the vanes dictate the patterns of the holes. You can't run the holes in the same pattern as the vanes.

[StickMon]

Sorry to belabor what's probably an insignificant point, but the stock ones look like this.
Compare and contrast with the pics in my first post.

[The HACK]

The position of the vanes dictate the patterns of the holes on a drilled rotor. You CANNOT have the holes run in the same exact pattern as the vanes.

I'll bet if you look at the drilled holes and the actual position of the vanes, they may go in the same rotational direction but they do not match up.

There are no such thing as "the right direction" for the drilled holes. I'm going to do what I can to explain it in word, but the only way to comprehend is if you can cut the disc open radially and see the vanes in relation to the holes.

First, the holes can not go through the ribs in the vane. That's fairly easy to explain. It'll dramatically weaken the rotor disc and disrupt the evacuating airflow. Second, the holes can not occupy an entire length of a vane, ie, you can't have multiple holes in each vane. The end result is, the pattern of the holes are dictated by how the vanes are actually shaped (straight, sweeping, curved, or converging), and how many vanes and how tightly spaced they are.

Functionally, there's little to zero effect as to the pattern of the holes. There's a slight difference when it comes to slotted rotors, whether the slots dig into the rotor or sweep back, although the slot pattern isn't dictated by the actual internal cooling vanes.