I know rotors should be installed per the manufactures instructions. And that the only important thing is to make sure the inner vanes are facing the correct way. But on straight vaned rotors does it really make a difference which way the slots face? I.e. whether they cut from top to bottom or bottom to top? Isn't gas removal the same? Discuss...

 

If the vanes are not directional it is my understanding that they can be installed either direction.

 

Looking at the car I have the vanes coming from the center of the hub rt so the center part of the vane hits the pad first.

 

I've noticed that different manufactures use different slotting patterns. Some do one way and some do the other. I guess it's just preference. My friend's Girodisc rotors run the slots one way and my DBA 4000's run them the other way. Both were installed per the instructions. I was just wondering if companies believe running the slots in a particular direction improves gas removal.

 

Differ companies have differ slot directions. The left/right should be marked on the rotors.

 

Well as far as i have heard on track from specialists if the manufacturer did'nt mark them left/right, 5 or less slots the outer edge of the curve should point to the rear of the car, more then 5 slots they should point to the front of the car. Dont know why, but that's just what i've been told and seen on most racecars that have 5+ slotted discs they almost always face forwards. perhaps someone can shed more light on the correctnes and why of this.

 

Slotting and drill patterns can face either direction depending on the vane design of the rotor. Pillar vane (or kangaroo paw per DBA) and straight vane can go any direction. Curved vane rotors need to have the vanes spiraling out and back from the direction of rotation regardless of what is on the face.

Martin

 

^Thanks Martin for confirming my assumption.

 

What do you mean out and back from the direcrtion of rotation?

 

I believe he is saying that the top of the inner vanes should be facing towrds the rear of the car if they are directional. the outer design doesnt matter and if they arent labeled your gonna have slots on one side facing opposite just becuase all four rotors were designed with the same dirrection. but unless its a directional vane rotor it shouldnt matter.

 

If you look at the top vein it should curve the direction a c would curve (towards the rear). That's how I understand they go, that is suposed to help with venting or removing brake dust (I forget)