Liz Miles
January 1, 2013

No amount of horsepower in the world is going to help you around a tight autocross track or short road course. Brakes, however, represent an area where overkill is OK. Choosing a caliper with enough clamping power to exceed your skill level can save you from yourself. Rotor choice isn't as obvious. Though the look of drilled and slotted rotors may be appealing, no track or autocross champ will tell you that drilled rotors are a good idea. They have a high failure rate due to cracking around the holes. Slotted rotors, on the other hand, are extremely helpful. The slots are not to remove heat, but rather to let gasses produced by the pads escape. Without the slots, the pad can kickback from the pressure. The thickness, veins, and diameter of the rotor are what determine its cooling ability. The vents between the front and back rotor face take in air from the center and push it through the rotor and out the perimeter. A cheap way to help cool the brakes even more is to route ducting from the front or underside of the car to the brakes as close to the center as possible.

Brake pad material varies from street to track. Street pads (lower pad pictured) are designed for quiet operation and long life more than anything else. A race pad is designed for maximum grip in extreme heat and nothing else. The materials for race pads (upper pad pictured) may need to be heated up to work properly and shouldn't be used on the street in many cases. Any brake pad change should be done in conjunction with a rotor resurface or at least a scuff. The brake pads will not grip properly if they are put to a shiny rotor surface. A brake-in or “bedding” procedure should also be performed at each pad change as well. This consists of three or four medium stops in a row, a cool down cruise, and six or seven aggressive stops.

The brakes should be given a quick bleed before each event to clear any air bubbles that hinder braking performance. Old brake fluid can have a low boiling point and could have absorbed water. Anything in the brake lines besides brake fluid can make the brakes soft and unpredictable. A good flush is a good idea if you're not sure what the condition of the fluid is. Brake fluid prices are all over the place but you don't need the most expensive stuff. Sittner has had a lot of success with Ford's Motorcraft brake fluid, as it has one of the highest boiling points available. It's inexpensive and readily available.

Tech Inspection
You may think you're safe and ready to run at the track or autocross venue, but a tech inspection can catch you off guard unless you're prepared. Every organization has some sort of tech inspection to keep you and your fellow enthusiasts safe. It's wise to print out the tech sheet provided by each organization and perform a tech inspection on your own prior to the event. This will help ensure there's nothing left unknown. This is a sample from the Northern California Shelby Club, a group Sittner works with frequently. They provide a pre-technical inspection form for this very reason, to make sure everyone is prepared for the track. A tech inspector will always check your car for a rigid seat mount and acceptable brake pedal pressure if nothing else.