Brake FAQ

Main areas to upgrade brakes and why:

1. Rotors – slots to release gasses
2. Rotors – slots to release gasses and drilled holes to lower temperatures. (risks involved with cheap rotors)
3. Brake Pads – Ceramic, Metallic, Semi-metallic, etc.
4. Big Brake Kits – Larger rotors and either caliper relocation brackets, or new calipers and pads.
5. Other Model Upgrades – taking brakes from a similar car and adapting them to your vehicle for better performance.
6. Stainless Lines and Performance Fluid.

Slotted Rotors

1. Slotted rotors will help the pad surface remain clean and help vent gasses created by the pad surface heating up, maintaining proper contact between the rotor and pad.

Slotted-Drilled Rotors

2. Slotted-Drilled Rotors can do what slotted rotors do as well as keep rotor temperatures down. There are 3 different designs to a “drilled” rotor.

The cheapest is taking a solid or slotted rotor and cross drilling holes in it. Some drawbacks to this are the fact that the heat from drilling process changes the hardness of the metal right at the hole and makes the rotor harder and more brittle inside of the hole. The holes can develop stress fractures around the holes due to the different temperatures and hardness of the rotor face and the surface of the hole. (the face heats up, and the hole doesn’t because there is no pad contact). This can cause the metal to expand and contract at different rates, resulting in stress fractures and cracked rotors.

A way to minimize this is to chamfer the holes. This is similar to “countersinking” a screw hole. The edge of each hole is expanded right at the face of the rotor, creating a “ring” of non-contact area on the face of the rotor. This is a sort of temperature transition zone that transitions the higher heat of the face to the lower temperature of the surface inside the hole.

The ideal way to make a “drilled” rotor is the way Porsche does it. The expensive way. Cast the holes in when the rotor is made. This eliminates the hardness/brittle problem because the rotor is created using a single process, resulting in a uniform hardness consistency throughout the metal. These of course can cost up to $500+ per rotor.

Brake Pads

3. Brake Pads – This one is fairly simple. Take two bolts off the caliper brackets, compress the brake pistons with a caliper tool or a block of wood and a C-clamp, replace the pads, and put them back on. Voila! Instant improved braking.

Now, what compound/brand to use. That one will require some evaluation of your requirements, budget, driving habits, and preferences. There are 3 basic tradeoffs when considering pads for your ride:

-Brake Dust (better bite usually means more dust); how clean do you keep your wheels and how much do you care?

-Temperature dependency (How well do the pads work when they are cold?); do you really want to be driving down the street and have to “warm up” your pads before you can stop quickly?

-Rotor wear (better biting pads are not rotor friendly) If you pay a ton of money for rotors, you may not be happy to replace them every time you need new pads.

Generally, brake manufacturers rate their pads for stock, performance street, street-track, and track use. These are good guidelines to go by, remembering as a rule of thumb that as you go from stock to track, you increase biting performance, brake dust, rotor wear, cost, and temperature operation. The last one meaning as your pads get more aggressive, the warm-up time increases.

Big Brake Kits

4. Big Brake Kits – Very simple physics. Larger rotors create a larger lever. It’s easier to stop a bicycle wheel from spinning by grabbing the outside of the tire as opposed to grabbing the brake disc attached to the axle. The less expensive kits just add larger rotors to the front and relocate your stock calipers. Very easy to do yourself. Complexity can skyrocket from there as you put new calipers, lines, pads, rotors, and that’s just the front of the car. You see where this is going. Don’t forget to replace those wheels with ones that have more clearance, your old 16″ers for the winter just won’t do it anymore.

Brake Swap

5. Swap on brakes from a model car that has better ones than yours. Luckily, Suby’s are somewhat like legos. Parts can fit from one model to another with minor modifications. The legacy rear brake upgrade is common for WRX’s. The 06′s come with a 4-piston front caliper and 2 piston rear caliper and are direct bolt ons for older WRX’s. The STi Brembos are also a commonly added part to a WRX. Most of these require 17″ wheels or larger, to accommodate the larger calipers and sometimes rotors.

Lines and Fluid

6. SS lines and Performance Fluids do nothing to improve braking distance or lower rotor temperatures. They do improve durability and pedal feel and are relatively inexpensive methods to improve driver experience. Are they necessary? Only you can decide. It’s well known that a short shifter doesn’t help you shift quicker, but it improves the overall “feel” of the car and your driving experience. Stainless lines and performance fluid will do the same for your brakes.