It depends on vehicle weight, MPH, rotor to tire diameter, pad surface area and compound, number of caliper pistons, piston diameter, brake pressure, stopping distance, and any other assistance such as a chute. I’m not trying to be difficult, there’s just a lot of factors to consider.
If the vehicle has four wheel disc brakes that are properly sized, proportioned, and with new pads you should possibly get half to a full season from the pads. Rotors should only be resurfaced when they show signs of warpage. Discoloration might be an indicator that a problem exists, but are not a reason for machining. Accumulation of pad material can often be removed simply with sanding disc and an air drill. If you are replacing pads more often on the front or back, and rotors show different signs of discoloration there might be an issue with the proportioning or improperly sized brakes. If you log your runs and check periodically, you will learn the pad life you can expect. At the end of the page are included specs on pads and rotors. As you will see, unnecessary machining of the rotors will shorten their life.
With two wheel disc brakes it depends on MPH and whether or not the driver is pulling the chute. Dragsters running in excess of 160 mph should always pull the chute. The chute scrubs off a lot of MPH once it is deployed and lightens the load placed on the brakes. Calculating kinetic energy in which velocity is squared, makes increased MPH a real issue. If pulled, you could expect a set of pads to live half to a full season, and rotors several years. If not, pads maybe every four races and replacing the rotors once a year. Many that don’t pull their chute, will opt for our 2 piece stainless steel rotors (B2794LS / B2794RS) which, in this case, last about two years before requiring resurfacing.
Steel Rotors – 10″ New .250″ (Discard at .215″) / 11.250″ New .355″ (Discard at .312″) / Pads New .480″ (Discard .200″) Measured including backing plate thickness.