Slotted rotor slot direction, different between manufacturers?

[Scin]

I found it interesting that my previous brembo slotted rotors and my new powerslot rear rotors have the slots in the opposite direction of my Stoptech rotors. I followed the manufacturer indicators for both, I even thought Stoptech may have had them backward and verified the direction by pictures on their website.

So with left being forward, my powerslots are like < while my Stoptech's are like >.

Is there any science behind this? I know each manufacturer is adamant about them being placed on the correct side, and my guess was because of the slot direction.... if this is the case why in the world would they differ?

 

[nsxtasy]

I don't know exactly why, but when I got my Stoptech rotors, I verified with them that their slots appear to go in the opposite direction from other manufacturers and it's intentional.

 

[Whatwasthat]

I've seen this too. I found out tho, that on some rotors, the slot goes all the way to the inside (the hub) past brake pad surface contact, and when you're braking, all the dust gets swept to the inside and released. I always thought it had to go a certain direction for the vanes to cool the rotors. I guess there's a big difference between just slotted rotors and drilled rotors. I've noticed most vented cross drilled rotors have to spin forward for the air to get scooped up by the vanes, while just slotted rotors seem to go backwards. But then again, they do differ by manufacturer.

 

[NSXDreamer2]

The slot direction should not matter as long as the vane is not directional... You always want to mount according to the vane direction. As it spins, the air is drawing from the hub, instead of pushing air into the hub. If the vanes are not directional, you should be able to swap in either direction disregard the slots orientation...

 

[nsxtasy]

The slot direction should not matter as long as the vane is not directional... You always want to mount according to the vane direction. As it spins, the air is drawing from the hub, instead of pushing air into the hub. If the vanes are not directional, you should be able to swap in either direction disregard the slots orientation...

I believe the Stoptech rotors have directional vanes.

 

[NSXDreamer2]

yeap, so I'm suggesting he can swap the powerslot rear (which is not directional) to match the slot direction to the stoptech fronts. If the slot direction border him at all...

 

[titaniumdave]

All that matters is the direction of the vanes, they should face so the curved, outer most edge of the vane points to the rear of the car when viewed from the top. The vanes are like the blades of an impeller, and this pushes the air out of the rotor as it spins.

I have had some Wilwood rotors which were slotted in both directions, alternating, so I am sure the slots will work no matter how they are oriented.