I have the Euro spec x-drilled M3 floating rotors from AA:
http://www.aatuning.com/brakes/e46brakes.cfm
The are unidirectional, but there are no instructions as to which direction they should rotate? Of course they are all out of the box, so I can't tell which is right or left. :(

I did a quick search on the web and found this image:
http://www.mindspring.com/~robert.mcdaniels/images/Rotor3.jpg
The red lines represent the vent fins inside the rotor.

Is this the correct rotation for these rotors?

Thanks

I have the Euro spec x-drilled M3 floating rotors from AA:
http://www.aatuning.com/brakes/e46brakes.cfm
The are unidirectional, but there are no instructions as to which direction they should rotate? Of course they are all out of the box, so I can't tell which is right or left. :(

I did a quick search on the web and found this image:
http://www.mindspring.com/~robert.mcdaniels/images/Rotor3.jpg
The red lines represent the vent fins inside the rotor.

Is this the correct rotation for these rotors?

Thanks
Yes, the image you have is correct. The idea is for your rotor to act like a centrifugal pump. It sucks air through the center (small diameter) and pushs it out on the outer edge (large diameter). As you notice, at the small diameter section (center) each channel not only has a smaller cross section (naturally) but also it leads its own end section (outer edge, large diameter) angularaly by a few degrees. The direction of rotation is determined by that angular delta. You want the end section to lag the beginning section of individual air channels. I hope this helps.

In other words, the opposite direction in which these unidirectional rotors have been installed;

http://www.9xproductions.net/usc/images/IMG_0691_jpg.jpg

:D

Thanx, found the little "L" and "R" etched into the sides. Installed and looking good.