Rick Johnston was working on his Factory Five Racing MK4 AC Cobra replica (shown above) and wanted an upgraded braking package. His solution: custom brackets waterjet cut from stainless steel by Big Blue Saw.
Once he's tested out the parts and worked through any bugs, Rick plans to make the designs public. For now, here's a sneak peek at the custom braking package partially assembled.
Rick gave us some technical details on the how and why of his design.
The design is modular and covers both the front and rear brakes. The outer bracket you see on the rear brakes is also used in the front. This is why there are 2 additional “outer brackets” (“L” shaped) in the part outlines [shown above].
This allows the mounting of front brake packages to the rear. Cobras are different than most production cars that the kit industry borrows parts from. Cobras have a typical front to rear weight balance of 55% - 45%. Additionally the center of gravity height is MUCH lower than a typical production car measuring approximately 15” in height. Also the tire Diameters remain quite large for such a low CG height. This means that this kit needs a lot more rear brake than the standard parts provide. My equations (not proven yet) should reduce the pedal force needed from around 150 lbs to about 40 lbs to lock all 4 wheels in a balanced manner (fronts locking slightly before the rears). I am working on another design very similar to this one, that would allow standard production 13” Mustang Cobra brake components to be used that would further reduce cost to builders.
And one more look at Rick's ride.
Note that when Rick ordered, he took advantage of our best tip for saving money on waterjet cutting: putting several designs into the same file. If you've got many parts all made from the same material and thickness, it's most cost effective to put them all into the same file before uploading them to the online quoting system.