OK this has been driving me nuts. I bought Baer Eradispeeds a while back and the directions were pretty clear about how they were to be mounted. But I thought for certain I had seen rotors installed with the slots and holes oriented BOTH ways or different vehicles.

Well today I saw another thread on rotors, and noticed the orientation on the right front wheel. Then looked up another thread to find a reverse orientation shown.





OK, so which way is correct? Or doesn't it really matter? Or are some rotors different from others in this respect?

 

The top photo is correct. (The Z06 Wheel)

That has been the big issue with the C6 Z06. All rotors are marked LEFT which makes the rotors mounted on the right side wrong!

 

[QUOTE=Chalky]The top photo is correct. (The Z06 Wheel)



The easiest way to determine wether your rotor orientation is correct; is to take a look at your rotor vanes. If they (the leading edge) are cutting into the air during forward rotation they are correctly oriented. If they are not, then they should be installed on the opposite wheel.

 

The upper photo is actually what it shows in the directions I got from Baer for my Eradispeeds. But some things just seem nonintuitive about it. For instance, what about the milled slots on the surface? What are they supposed to do? If they are supposed to allow hot gases or even water between the pads and the rotors an escape route, why are they oriented to go AGAINST the centrifugal forces the rotating rotors are applying? Wouldn't you want that to be slung to the outside edge of the rotor instead of being forced to the inside?

However what is very misleading is that according to the directions from Baer, the internal rotor vanes themselves do NOT cut into the air as the rotor rotates. It's the opposite, they are apparently used to draw off the heat from the center and EXPELLED at the edge of the rotors. For more on this, take a look at the Baer webpage showing the proper orientation:

http://www.baer.com/Support/TechTips.aspx?TechTipID=2

Personally this is still confusing to me. Are the plain rotors different in how they must be oriented as compared to the drilled and slotted rotors? Are the internal vanes one way in the plain and the opposite in the drilled and slotted ones? Although I don't think so, this is not really clear from Baer's tech tip page.

 

Err, the 2nd photo looks correct to me.

Look at the edge of the rotor; that would determine the "proper" orientation.

 

I just put mine on Sunday The rotors are stamp RL, RR,FL AND FR AND they match the 2nd photo .

 

I was pretty sure that the internal veins (the ones you can't see) are what matters those need to expell heat away in the right direction

 

the drilling and slotting has nothing to do with the orientation. The veins of the rotor do.
The internal veins should be racing backwards on top of the rotor.

 

[QUOTE=hightest] If you mean the vanes on the top of the rotors are pointed forward "cutting into the air", then you're totally wrong. The internal vanes of the rotor do not grab the air and try to force it inwards. The exact opposite happens. The vanes are "throwing off" the air inside of the rotor, creating a partial vacuum that draws air into the center of the rotor. If the vanes were straight, the direction of rotation wouldn't matter. Since they are curved and therefore directional, they pump more air when correctly oriented. If you want some proof, go to the DRM website and look at their C5 front brake duct kit and add on mounting bracket. These parts take air from the openings in the front and direct it at the wheel hubs. A lot of C6 guys with the Z51 drilled and slotted rotors have been in a tizzy the last year because the factory has been supplying the same front rotors for both sides. The official company line about this is that "there is not a significant (10 %?) loss in cooling."

 

 

I just installed my A/C Delco rotors. The vanes are designed to "pull" the heat out from the hub by creating a slight vacuum, not push air downward.
This is my right front. You can just barely see the vanes leaning backward.........I painted the outer edge and the hat first.

 

The internal vanes on a rotor are essentially the same as the vanes on a centrifugal pump. The intake to the "pump" is the center of the rotor and the outlet is the outer edge of the rotor. The result is as you describe - they suck air into the center and expel it at the edge.

For any rotor, the correct orientation is to look straight down at the top of the rotor and ensure the vanes are pointed to the rear of the car. As mentioned above, making this confusing is that GM didn't make right and left rotors for the C6 and C6 Z06 so one side (I think it is the right side) are on backwards.

 

quite correct

 

Some of the others are backwards compared to Eradispeeds.
AU N EGL and Mike Mercury are quite correct! The top photo is correct for Eradispeeds.

 

RICH Z wrote: "Personally this is still confusing to me. Are the plain rotors different in how they must be oriented as compared to the drilled and slotted rotors? Are the internal vanes one way in the plain and the opposite in the drilled and slotted ones? Although I don't think so, this is not really clear from Baer's tech tip page."

It's confusing because, as pointed out by several folks, different manufacturers take different approaches relative to the slots/holes in their discs. For Baer, the top picture is correct. For most others, including GM's own high performance rotors, the bottom picture is correct. AU N EGL posted the key determinant, which is how the internal vanes are oriented, along with the best explanation - he's a wise man, heed his words.

 

Baer usually marks their rotors with a "L" or "R".

This was done according to the label and is correct.