* Source: digitalcorvettes.com

If you are planning to purchase performance brake rotors for your vehicle, you should study brake rotor vein design before making your final decision about any brake rotor design, brand, and type. 

High end brake rotors utilize highly tested and/or patented designs that are very effective at dispersing heat, while stock rotors are much less apt to do so.  When performance brake rotors are engineered at the factory, they are done so to maximize surface area and modify air exchange to some degree. 

A well designed high performance brake rotor will be engineered to work much like a heat exchanger, and serve to evenly disperse heat across the brake rotor in a highly efficient manner.

A stock brake rotor, on the other hand, will have a less of a focus on increasing the heat exchange rate of the rotor itself, and a greater focus on lowering the overall cost of manufacturing the rotor.  The main disadvantage a stock rotor has over a high performance or racing style rotor is lack of surface area built in to it.  Because brake rotor plates are much closer together in stock rotors, as opposed to a racing style of rotor, and without a fancy vein design, air circulation is cut down immensely. 

You can expect the cooling capacity on a stock or poorly designed brake rotor to be sub par overall, so keep this in mind when deciding on more aggressive brake pads or caliper upgrades later on to further increase braking performance.

* Source: bimmerfest.com

Here are the most common types of brake rotor vein designs:

 * Source: socalevo.net

Straight Vein- This is the most common type you will find.  This style of brake rotor has the lowest cooling capacity, but it is the lightest overall due to its reduced amount of material content. 

Variable Vein-  This brake rotor style is similar to the straight vein rotor design, but comes with a variation in vein pattern to disturb air flow across the brake rotor plates.  This air turbulence that is created aids the dispersing of heat at an increased rate.

Pillar Vein-  Brake rotors with the pillar vein rotor design are similar to variable vane rotors, but have a more predictable pattern and are not generally patented.

All three of these brake rotor designs are mirrored when made for either side of the vehicle (right, left).

High performance brake rotors made for high performance or racing vehicles typically employ curved vein designs.  Curved brake rotor designs are not only great at cooling the brake rotor efficiently, but aid to increase the strength and reliability of the rotors.  The veins in these designs deliver the greatest amount of brake rotor surface area thereby acting much like a heat sink. 

Due to the curved vein design, air is now semi-pressurized before it leaves the surface of the rotor, thereby leveling out the heat signature of the brake rotor.  An uneven brake rotor heat distribution pattern can lead to cracking, which drilled rotors are notorious for.

Most people do not consider rotor vein design geometry when choosing a brake rotor set for their vehicles, however they are the greatest factor in determining the cooling efficiency of the rotor overall.  Study the manufacturers of the rotors you plan on buying, and make an informed decision for yourself and your vehicle.