• It is a sad truism in the automotive world that the best tuners know practically nothing about brakes. Though these hydro-mechanical systems are fairly simple in design and intent, there are a lot of factors that come into play where performance and repair are concerned. A general misunderstanding of a braking system's function and operation has let to a proliferation of myths about them, and rotors in particular.
  
  

Big Brakes Stop Faster

• Drive down any Main Street in America for more than five minutes, and you're sure to spot some car or truck with larger-than-stock rotors. The popular idea about larger brake rotors is that they will make your car stop faster, but this couldn't be further from the truth.
  
  It is true that larger rotors can give your braking system more mechanical leverage when it comes time to stop, but this effect depends greatly on how efficient your stock system is in the first place. The reality is that braking performance has a lot more to do with the brake pad material and brake system pressure than rotor size. A brake caliper can only squeeze the rotor as hard as the master cylinder will let it, and increasing the pad's contact patch beyond what the system pressure can utilize will actually lead to a decrease in braking performance.
  
  Big brakes are designed primarily to prevent overheating under continuous usage on the race track. Better brake pads may not be aesthetically glamorous, but they will cut stopping distances far better than bigger brake rotors alone.
  
  

Vented Rotors Eat Pads

• Vented (slotted) rotors are used to evacuate the gases that build up under a brake pad and prevent it from gripping the rotor. There is a common belief that slotted or drilled rotors will destroy your brake pads, but this generally only applies to the poorly machined rotors of decades past. The slots or holes on modern vented rotors have beveled edges to prevent undue pad wear.
  
  

Warped Rotors

• There is a commonly held belief that disc brake rotors often warp under heat, which causes them to become wavy and cause pedal vibration. This belief is reinforced by the fact that this pedal oscillation disappears after the rotor is machined flat again. More often than not, this "warpage" is actually the result of an uneven buildup of metallic pad material on the rotor face. Before replacing your "warped" rotors with new ones, have them checked by a qualified mechanic with accurate equipment. If the disc is not warped the same amount on both sides, then your mechanic need only shave off the extra pad material on one side.