Brake rotors - Vane direction??

[mazdilla]

OK, so my buddy and I disassembled my brakes, stripped all the rotors off, were about to start on the brake lines and realized that I need some grommets for the rear SS lines to fit in the bracket.

I shoot down to HH for a pair of grommets, come back, only to find my buddy standing there pleased as punch since he has the new cross-drilled rotors installed. I look at him and ask the simple question, "Did you read the boxes? You do know that there is a left and right side for drilled rotors, RIGHT ??? " He looks at me as if I have two heads. I show him the boxes. He says, "Oops!"

Anyway, I think they are on wrong. He has each side of the car with the drill pattern sweeping from hub center up and forward.

I know on the fronts, that the pattern should sweep from hub center up and back away from the caliper. In other words, up and out towards the rear of the car.

I am assuming that the rear drill pattern should be the opposite. Since the calipers are mounted at the back of the rotor, the pattern should sweep up and out towards the front of the car.

Am I correct?

[Donutz]

It is different, and you should refer to the manufacturer. When you refer to the 'vanes' are you referring to the channels inside the rotor, or the pattern of the drilled holes? The vanes inside the rotor will either be directional or straight. I want to make sure we are referring to the same thing before I provide any advice.

[mazdilla]

It is different, and you should refer to the manufacturer. When you refer to the 'vanes' are you referring to the channels inside the rotor, or the pattern of the drilled holes? The vanes inside the rotor will either be directional or straight. I want to make sure we are referring to the same thing before I provide any advice.

Magnum Cross-drilled rotors. Cadmium coated.

There are no vanes, I was referring to the pattern of the drilled holes.

Thanks!

[WingZero_]

It's different for different vendors, but most cross drilled go so the highest drill hole is forward like this:

http://img132.imageshack.us/img132/6015/spdrilledbg.jpg (http://img132.imageshack.us/i/spdrilledbg.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Or like this guy is doing.
http://www.youtube.com/watch?v=DqYY-OfhEaY

[Donutz]

^^ Yes, like that, unless otherwise specified by the manufacturer.

[mazdilla]

Then I'm OK.

Thanks, Guys.

[WingZero_]

No prob

[mazdilla]

I used the search engine here and couldn't find a thing. I do a google search and end up with this:

http://www.torontomazda3.ca/forum/showthread.php?17938-Cross-Drilled-Rotors

Thanks again!

BTW, my buddy took it upon himself to change them to the other direction even after I left him a note this morning that indicated they were installed properly. He looked at the note, but obviously didn't read it thoroughly. LMAO... he's becoming real adept at changing rotors on a Mazda 3.

Maybe I'll get to drive the car after work tomorrow.

[Dave_The_BMXER]

Wow you guys freaked me out as mine are installed the other way. However I have straight vanes.

[mazdilla]

Wow you guys freaked me out as mine are installed the other way. However I have straight vanes.

The vents in the Magnums (front) are straight as well. There are no vanes or slots. The rear rotors are solid, but drilled in arc patterns.

Thjese pics were borrowed from this thread: http://www.torontomazda3.ca/forum/sh...Drilled-Rotors (http://www.torontomazda3.ca/forum/showthread.php?17938-Cross-Drilled-Rotors)


Rotor Set for 2.3
http://img177.imageshack.us/img177/6602/dsc01498hh3.jpg

Front
http://img264.imageshack.us/img264/4471/dsc01499ou2.jpg


Rear
http://img239.imageshack.us/img239/2838/dsc01506ie8.jpg

My set has the same part numbers, but is cadmium coated.

[Dave_The_BMXER]

So if the vanes are not directional does it really matter? From what I read it should go with the direction of the vanes whatever that may be.

Visually mine look 'backwards' though based on this thread.

[WingZero_]

If they work I wouldn't worry about it. I mean the concept behind dimples, slots, drill holes, etc is all the same. It lets the heat and gas that is cause while braking to escape. Just some manufacturers say they are supposed to go on a certain way. Both cars I used this type of rotor on, the "vanes" were as shown above and in the video I posted.