Project 5.0 Mustang (The White One) Making it Stop with Essex Parts AP Radi-CAL Brake System


OEM once piece rotors distort into a cone shape under hard use due to heat and their attachement to the car's hubs on one face. This face tends to run cooler due to conduction and the rotor distorts into a cone due to the temperature differentials between the faces. 

AP Racing's two piece rotors have slotted attachment holes and are attached to the alloy hat with bobbins. This allows the rotor to float and freely expand as it gets hot. The free to move rotor stays round and flat, giving the brake pads a nice and flat surface to work on. This makes for more efficient and consistent brakes under all conditions. 


The rotor bobbin is held in place by an aircraft NAS bolt using a temperature resistant eccentric thread jet nut. This is sorta like an all metal nylock nut that works at high temperatures.

The bobbin allows the rotor to move in its radially oriented slot as it expands. The rotor floats with about 0.012″ of play and to keep it from rattling too much on a street-driven car, a spring steel anti-rattle clip keeps the rotor in light tension to the hat while still allowing for radial moment.


Here is what the assembly looks like when attached to the rotor. It is easier to visualize how the anti-rattle clip works when viewed assembled!
Essex Parts brake kits come with DOT approved Spiegler Performance Parts braided steel brake lines. The brake lines use high burst strength, non-expanding Teflon lined stainless hose for good brake pedal feel and improved brake efficiency. 

The lines' banjo fittings can rotate 360 degrees for perfect alignment and less strain on the hose. The fittings also have anti-whip plastic inserts to reduce the likelihood of fatigue failures. The lines also have an abrasion resistant sheath for longer life and less snagging and chafing of the lines on other parts of the car.


Stainless steel mounts for the brake lines for a perfect, zip-tie less fit are included in the kit! We wish more brake kits had nice touches like this. 
The Essex Parts brake kit came with Ferodo Super Formula racing brake fluid. The Super Formula fluid has an amazing dry boiling point of 622 degrees F with a wet boiling point of 392 degrees F. This is a better wet boiling point than your typical DOT 5.1 street fluid and excellent for a racing fluid. Super Formula brake fluid has a relatively low kinematic viscosity of 1500 centistokes.  This means it is not too thick and compatible with OEM ABS systems. 

The Essex Parts AP Racing big brake kit is a whopping 11 lbs a corner lighter than stock, much of this in rotating weight. About two pounds of this saving is also due to the unique Radi-CAL brake caliper. This is a huge 22 lbs right off the front of the car where it matters the most as it is both rotating and unsprung weight. 

The Essex Parts brake system for our Mustang is so unique and we were so impressed, we felt that we had to share some of the technical details of it in a stand alone article before we installed it. 

Stay tuned, we are currently building a complete high revving NA Coyote motor for our Mustang, after which we will show you the installation of these brakes.  Once the engine is in, it will be back to the track to dial the car in and compare it to what it did stock when we started this project.

The best is yet to come!

Read more about project Mustang!


Essex Parts

Ford Racing

CSF Radiators

Addiction Motorsports

SCT Performance

West End Alignment

Borla Exhaust

AEM Intakes

HRE Wheels

See More of Project Mustang in the HRE Wheels Gallery

Nitto Tires


KW Suspension



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