[89Trooper]

When installing drilled or slotted rotors, which way do they go on? Do the holes at the outer edge of the rotor hit the brake pad first? Or, do the holes nearest the hub hit the pads first?

So, in the pic, is the rotor on the bottom left a front right rotor, or a front left rotor?

Thanks for the help!



<font size=-1>[ This Message was edited by: 89Trooper on 5/21/06 6:46am ]</font>

 

[2FST4U]

I don't think it matters for the rotors you pictured; they aren't using directional vanes to cool them.

 

[89Trooper]

I also think the holes have to be oriented in a certain way for proper heat dissipation.

 

[OleDutchD]

Hardly consider myself an authority, Trooper, but if it were me, I'd install them so that the holes nearer the center hit the pads first. That way, any gases and brake dust/debris are centrifugally expelled away from the hubs and out away from the rotors.
And, yes, those would appear to be directional. The pair on the left look to be for the driver's side, the two on the right would seem to be for the passenger's side.

Just my cheap $.02

Best of luck,

Kevin

 

[GMH351]

Check out baer brakes.

http://www.baer.com/

It looks like you have slotted rotors.
I believe they say to place the rotor with the vanes pointing to the direction of rotation. That is slot/rotor outer edge first rotating forward. Hope this helps.

I'm looking to add these on someday, good luck.

 

[GMH351]

Front right.

 

[89Trooper]

See the problem I'm having? That's:

2 for one way, 1 for the other, and 1 indifferent.

 

[coolfalcon]

Which direction should the discs rotate?
It is a popular misconception that the slots or drillings in a disc determine the direction of rotation. In truth, for an internally vented disc, the geometry of the vanes dictates the direction of rotation. There are three vane types in use:

* Straight
* Pillar vane (comprised of many small posts)
* Curved vane

The first two vane types are non-directional, and can be used on either side of the vehicle. The curved vane disc, however, is directional. A curved vane disc must be installed with the vanes running back from the inside to outside diameters in the direction of rotation. Please see figure. Orienting the disc in the manner creates a centrifugal pump. The rotation of the disc causes air to be pumped from the center of the disc, through the vanes, and out through the outside diameter of the disc. This greatly enhances the disc's ability to dissipate heat.

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.
I didnt see any pictures there.
http://www.buybrakes.com/brembo/faq.html#q28

 

[66GT289]

Finally a subject I know something about.....
Coolfalcon is correct regarding the internal vanes.
The rotors pictured appear to be straight vane, so they
can be oriented any way you desire. Once they are
slotted, however..... the lower left rotor in your photo
would go on the the Driver's Side of the vehicle.
Back in the days when I used to do race car brakes,
before it became common-place to have slotted rotors,
we used to do them custom on our mill at Global West.
There also is a right and wrong way to machine them.
We used to cut fairly narrow slots starting from the hub
and working out to the rotor's edge. Slots should have
a slight curve to them. The straight style slots are far
easier to machine or cast in place but are more of a
"cheese grater" on the brake pads. All slots should stop
just shy of the outer edge of the rotor. The depth of
the cut is to the rotor's "throw away" dimension.
There are other particulars, but I won't bore you

Akebono Brake Corp
Farmington Hills, MI
Tokyo Japan

 

[1 Bad 88 GT]

The pair on the left are PS rotors.


BTW I do not like drilled or slotted rotors at all due to their tendency to crack radially from the holes or slots.

 

[89Trooper]

BTW I do not like drilled or slotted rotors at all due to their tendency to crack radially from the holes or slots.

Not a problem for a daily driver. I wouldn't have them if I was auto-crossing. They are more for looks, but I still want to install them correctly.

The pair on the left are going on the driver's side. That will take water/gases outward from the hub as said earlier.