Slotted and Drilled Rotors Directional???

**CWW17** · 10-18-2007, 07:52 PM

This may sound dumb... but are slotted and drilled rotors directional? Should the lines on the rotors be flowing with the wheel rotation direction or against it?

**mbrownin** · 10-18-2007, 08:18 PM

They are directional. You want the end of the slot that's closest to the center of the wheel to lead the way when rotating.

**CWW17** · 10-18-2007, 08:21 PM

forward? As in with the wheel?

**CWW17** · 10-18-2007, 08:23 PM

Like this for the drivers side?

**oneBADDz** · 10-18-2007, 08:26 PM

Originally Posted by mbrownin

They are directional. You want the end of the slot that's closest to the center of the wheel to lead the way when rotating.

incorrect. ebay sellers say so, but if you get any from major companies they go against the rotation of the wheel. the end of the slot farthest from teh beter to lead the way. They look better the other way, but they actually go opposite of how they look like they should. Reason being is that good rotors have directional veins inside and the veins must be curved opposite from the slots for the integrity of the rotor not to be compromised, and the veins HAVE to run a certain direction to properly cool the rotor

drivers perspective looking forward from the driver's seat

**CWW17** · 10-18-2007, 08:28 PM

okay still confused.... in the picture I posted above, which side should that be?

**oneBADDz** · 10-18-2007, 08:31 PM

passenger. go to any rotor manufacturers site and check out the FAQ, the same question is answered in all of them, it's a common question for sure.

**FuhBreezeE** · 10-18-2007, 08:32 PM

I've seen people go either direction, mine are as stated above though.

**mbrownin** · 10-18-2007, 08:45 PM

Originally Posted by oneBADDz

incorrect. ebay sellers say so, but if you get any from major companies they go against the rotation of the wheel. the end of the slot farthest from teh beter to lead the way. They look better the other way, but they actually go opposite of how they look like they should. Reason being is that good rotors have directional veins inside and the veins must be curved opposite from the slots for the integrity of the rotor not to be compromised, and the veins HAVE to run a certain direction to properly cool the rotor

drivers perspective looking forward from the driver's seat

That is correct IF the vanes are angled. Lots of rotors don't have angled vanes, so the way I described is better for removing pad dust, etc. from the rotor surface for rotors with straight vanes. But if the vanes are angled, they should take precedence.

**oneBADDz** · 10-18-2007, 08:52 PM

Originally Posted by mbrownin

That is correct IF the vanes are angled. Lots of rotors don't have angled vanes, so the way I described is better for removing pad dust, etc. from the rotor surface for rotors with straight vanes. But if the vanes are angled, they should take precedence.

I bought sets of slotted roters from two different manufacturers and neither set had directional veins. Both of them had instructions that said to do it the way I posted. It looks better the way you said, but it is in fact incorrect, I'm not rying to start a war, but every major manufacturer agrees

**oneBADDz** · 10-18-2007, 08:54 PM

Straight from Brembo:

Additionally, all of Brembo's slotted discs are directional as well, regardless of the vane geometry. The discs should be installed such that the end of the slot nearest the outer edge of the disc contacts the pad first. Please see figure.

**SSTODD** · 10-19-2007, 08:31 AM

The manufacturer of mine told me the internal vanes are not directional so the rotor is not marked and can go either way? I was so confused I had them each way at the same time. Also our front caliper is at the back and our rear caliper is at the front so to contact the pad first wouldn't the driver side rotors each point different from the other?

**mbrownin** · 10-19-2007, 10:33 AM

Caliper at the front or back makes no difference. Either way, any given spot on the rotor will first contact the pad on the "right" side of the caliper, i.e. if you had a "Camaro" decal on the caliper, the side of the caliper on the "o" end.