As our Ford Muscle project 2001 Mustang Cobra, titled Project Apex, started to take shape and began making laps around the road course we ran into a big problem: stopping. We started going through front brake pads like a great white shark goes through teeth. In defense of the OEM Ford Cobra brake calipers that were on the front of the car, we had been upgrading everything else to make the car go faster: stickier tires, lightweight Forgeline wheels, a six-speed transmission, and a tuned suspension from Maximum Motorsports. All of these things made the car faster around the road course, which meant our OEM braking system had a lot more work to do to slow the car down before the next tight corner. We desperately needed an SN95 big brake kit before the front of the Cobra found a tire wall.
Even with aftermarket race pads and brake cooling ducts, the extra speed we had added to the Cobra was still too much for the braking system. The pads were wearing quickly and unevenly, showing signs the stock braking system wasn’t up for the track abuse we were throwing at it. These pads were definitely finished.
Here you can see the uneven wear on the pads as the two-piston OEM calipers couldn’t handle the brake forces. This is from about 8 sessions of track time. Normally in a build like this, you’d probably start with a better set of brakes to begin with, but we wanted to find the limit of the stock parts (for the sake of our readers).
Why We Needed A Brake Upgrade
The funny thing about needing to upgrade your brakes is you usually realize it when it’s too late. That was certainly the case for Ivan Korda, who realized we needed to upgrade the brakes on Project Apex as he was mashing the middle pedal to the floor as hard as he could, desperately trying to keep from crashing the Cobra at the end of a long straight. He said his eyes almost popped out of his head as the wall got closer. Nothing gets your attention quicker than that butt-puckering moment when you think the car that you have sunk hundreds of hours and thousands of dollars into might become upside-down and on fire with you inside. Luckily for Ivan, that did not happen. He brought the car into the paddock to inspect the situation. The situation was simple. This is when he learned the car he built for track days needed more brakes.
Even though we had already upgraded the brake fluid, the brake pad compound, and added slotted rotors, we were still using the OEM Cobra brake calipers. The stock Cobra/Bullitt brake calipers were a nice improvement over the Mustang GT calipers, but once we hit the track they just weren’t sufficient.
Allow me to nerd out here for a moment and “break” down some science on brakes. When a car is moving down the road, it has kinetic energy (energy involving motion). The amount of that kinetic energy depends on two things, speed and weight. The faster you are going or the heavier the car, this increases the amount of kinetic energy the car possesses as it is moving. When you want to slow the car down, you need to disperse that kinetic energy.
When a driver presses the brake pedal, known as the whoa pedal, this pushes hydraulic fluid through the brake lines, which applies pressure to pistons inside the brake calipers, which push brake pads against a spinning rotor. The friction between the brake pads and the rotor transforms the kinetic energy into thermal energy (heat) and the vehicle slows down. Too much heat is the issue plaguing our brakes. During a track day, brakes get hot, exceptionally hot, and brake components (fluid, pads, rotors, calipers) soak up that heat. Once they get too hot, they are no longer effective. Too much kinetic energy being transformed into too much heat means the pedal goes to the floor and the driver starts to think, “this is the end.”
How To Know When It's Time For A Big Brake Kit
When your braking system is overmatched by its demands, there are several signs:
- Rapid brake pad degradation: the material can actually start to crumble and does not wear normally (note: this can also happen when you have too low a temperature-rated pad as well)
- Brake pedal feel: in our experience, a spongy pedal is the number one culprit the fluid has been boiled and the bubbles trapped air in the lines
- Loss of stopping power: the pads can no longer apply the same friction on the surface of the rotor, which can be very scary when it happens unexpectedly
- Warped rotors: shuddering and brake pedal vibrations can happen when this is done long enough that the heat warps the rotors
Here we can see the stock Cobra calipers on the left and the 14-inch Extreme Plus Brake System from Baer Brakes on the right. The OEM Cobra calipers have four pistons whereas the Baer Brakes calipers have six pistons. The robust six-piston calipers can handle much more heat and ensure the pads wear evenly.
What We Did About It
To fix the problem of our car quickly becoming too fast at the track for the OEM brake system, we called in the experts at Baer Brakes. Rick Elam, from Baer, knew exactly what we needed, an SN95 big brake kit. We like things simple, and Baer had the easy-button solution for our problem — a bolt-on kit, with everything we would need for the Cobra and we wouldn’t even have to upgrade the master cylinder. Baer makes a number of brake upgrade kits that will bolt onto the spindle of a 1994-2004 Mustang, each of them at a different performance level and price. But after talking to Rick, we quickly realized our level of track usage required the Extreme Plus Brake System.
What we like about the Baer Extreme Plus Brake System was that it came with all the components to bolt the six-piston 6S caliper to the stock Ford spindles.
Elam dialed us in with everything we would need to get the SN95 big brake kit to work: the calipers, brake pads, rotor and hat assemblies, brackets, stainless braided brake hoses, and mounting hardware. The installation was simple with easy-to-understand instructions. We were able to install a larger brake rotor and large six-piston calipers because we already upgraded the wheels with Forgeline GS1R wheels. The point of the larger brake system (rotors and calipers) is the ability for more clamping force and heat dissipation.
The Baer D0731S brake pads are much larger than the OEM pads from the Cobra brakes. The pads have slots in the carbon ceramic pad material to allow for gas to escape.
Because we were going to take this Mustang directly to the track and beat on it, Rick suggested the race pad compound, which is the highest friction level that Baer offers. This pad works well under high heat, which is exactly what we need for success on the track. The entire SN95 big brake kit bolted onto the Cobra without any modifications or problems, which is what every shade tree mechanic is looking for in the garage.
One of the options we had when choosing our brake upgrade from Baer was the caliper color. Baer has multiple colors to select. We chose this gorgeous blue to compliment the silver paint on the Cobra.
SN95 Big Brake Kit Results
Baer sent us a template to use to ensure our SN95 big brake kit would fit inside the wheels. That wasn’t a problem since we had already upgraded the wheels to 18-inch Forgeline GSR1s. In fact, when we bolted the wheels on for the first time we saw there was plenty of room, which is good because when clearances get tight between brake calipers and wheels, rocks and other track debris can get stuck and cause damage. Also, the larger clearance helps with air movement and heat dissipation.
Our strong and lightweight 18-inch Forgeline wheels had enough space inside for the larger Baer brake kit.
With the new kit bolted on, we bled the brakes and are now ready for our next track day test. In our next installment of Project Apex, we test the improved braking ability of our Baer brakes as well as another suspension upgrade from Maximum Motorsports.
