Here you can see the difference between stock and the Wilwood six-piston caliper upgrade. Even drilled stock rotors couldn’t keep the brakes from fading when driven on a racetrack.
The Mini Cooper S enjoys a reputation as fun, zippy little car that handles great. Now that prices on used S models have come down, it’s only natural that people would want take them to the racetrack.
Patrick Orozco from In The Doghouse Garage bought one to use for Time Trials and racing, but when he took it out on track he discovered something he hadn’t counted on: brake fade after a couple of laps. It was serious enough that he’d have to pull into the pits or dial back the driving to the point that it wasn’t fun. And that’s, well, no fun.
To remedy the problem, he needed more stopping power and a front brake setup that generated less heat, so we called the folks over at Wilwood Engineering, an aftermarket brake manufacturer in Camarillo, Calif., that specializes in motorsports applications. Wilwood determined that the car would work best with its six-piston setup with special pistons to reduce heat transfer to the fluid and two piece rotors with aluminum hats.
The kit comes with everything needed to do the installation, from pads to hoses, brackets and hardware. And since Orozco lives near Camarillo, he took it to Wilwood’s shop at the company headquarters to do the project.
The installation took only a couple of hours, and it likely wouldn’t take much longer in your driveway or your garage. It is nearly as simple as a standard brake job. Just remove the old parts and put on the new. Yes, there are a few more steps, what with the adapter brackets and the like, but the installation went like clockwork. Here’s how it played out.
Before getting to work, Wilwood tetchnician Ryan Bushman lays out all the parts for the installation.The rotors have to be assembled. Using an aluminum hat attached to the steel rotor minimizes heat transfer.Bushman applied to each bolt a dollop of No. 516 Loctite, a thread sealant that provides excellent solvent resistance and an operating temperature range from 65 degrees to 300 degrees Fahrenheit.Each bolt on the rotor hat gets torqued to 155 inch pounds.After removing all the stock parts, Bushman mounts the adapter bracket for the Wilwood caliper using the supplied hardware. He used more Loctite 516 on these bolts, too.The bolts that attach the adapter bracket to the spindle are torqued to 60 foot-pounds.The Wilwood kit comes with locating rings to center the rotor hat to the hub rather than to the lug studs.Because the Mini will be use for Time Trials and racing, the calipers will be fitted with special pistons. They have an additional insert, which helps prevent heat transfer from the pad through the piston to the fluid. Note the standard pistons in the background.Bushman uses assembly lube before pushing the pistons into the caliper bores.Bushman inserts the piston into the caliper bore. Note how the Wilwood caliper uses different diameter pistons, which helps prevent pad taper in heavy-braking applications.The Wilwood caliper uses a unique pin system to hold the pads in place. The pins are held in place with snap rings that pop in and out easily with a small screwdriver or pick.Bushman uses Teflon tape on the threads of the fitting where the brake hose attaches. Note how the caliper has two bleeder valves so you can install it on either side of the car.Add Loctite No. 516 to the caliper-mounting bolts, too.Bushman installs the mounting bolts with the correct washers.Bushman torques the caliper to the mounting bracket.With the caliper mounted, it’s time to connect the hydraulics.Bushman routes the braided stainless-steel brake hose to the hard line on the chassis.The factory tab on the chassis accepts the new brake hose and retainer clip.Here you can see the difference between stock and the Wilwood six-piston caliper upgrade. Even drilled stock rotors couldn’t keep the brakes from fading when driven on a racetrack.With everything installed on driver side, repeat the process on the passenger side, bleed the system and you’re done. It’s worth noting that the wheels Orozco had on his car required spacers to clear the calipers.
