Which direction drilled rotors

Then it matters. I read that on the internet so I can sound smart here. I too installed them opposite of the image years ago. Good point on the directional vanes. I think it does matter. A little. Having the rotors installed the way that picture shows makes the slots more likely to "scoop up" air as they rotate, which would ostensibly help cooling. And that's supposed to be one of the purposes of slotted rotors.

I see your point. I was thinking the opposite - "throwing away" the heat. But if you think about it in terms of physics, cool air moving across or towards the rotor is more likely than heat being "thrown" off of the rotor. The way I understand it is that the rotor also acts as a heat sink. So cooling the rotor with air to maintain temperatures within a desired range is the goal, not trying to shed the heat.

This is exactly correct. Larger rotors are used on race cars for several reasons. Just trying to decide if the car should stay parked until my Friday's service appointment, and how gingerly I need to drive in when I take it in the 60 miles to get it corrected.

Appreciate 0. First Lieutenant. Originally Posted by msh There is no backwards or forwards with drilled or slotted rotors. Its a preference thing really. If you have the curve going towards the back of the car its overall good braking, if the curves are facing the front of the car people will tell you the pads bite harder thus stopping quicker.

I didnt notice one or the other personally. Originally Posted by DataStream Last edited by msh; at PM.. Hardest part is, since you have to get both wheels up at the same time to swap the rotors, is you'd have to put it on jack stands or use two jacks if you have them. Also for clarification: A dealer out of town cocked it up I was really curious if that would work. As long as I can go easy the next couple days and limp it in Friday for the fix, it'll work out.

PITA, though Well, BMW Seattle fixed my rotors, dd a service inspection on the car, and set the personalization on my blinkers how I wanted them 3-flash. Took them about an hour Friday morning and it gave me a change to order a handful o parts I needed, as well. Then I sat around for two hours while BMW Seattle called the other dealership to coordinate reimbursement on the brake fix.

What will happen? A few high performance rotors are directional, and they are marked as such. What about slotted or drilled rotors, though? In many cases, slotted and drilled rotors are not side specific as well. Some car owners believe that the presence of slots and drillings means that the rotors are directional.

The truth is that in internally vented rotors, the type of vanes determine whether or not the rotor needs has to be mounted on the correct side of the car.

Straight vanes and pillar vanes are non-directional. You can install straight vane rotors and pillar vane rotors on either side of the vehicle. Curved vane rotors are directional. When a curved vane rotor rotates, it creates a centrifugal pump. The rotor sucks air in from the center of the rotor, pumps it through the vanes, and out through the outside edge of the rotor. To install a curved vane rotor correctly, make sure the vanes at the top of the rotor are tilting rearward.

Keep in mind that a few brake rotor brands make rotors that are directional, regardless of the vane geometry.