The electric parking brakes are installed. I had been waiting to upgrade the rear uprights before finalizing the bracket design. Unlike the prior uprights, the new uprights are symmetrical and feature a thicker center web which comfortably accommodates a M10 screw. This makes drilling and tapping the holes to mount the bracket straight forward. I 3D printed mock brackets to ensure a good fit before having them CNC machined.
The heads of all of the screws (e.g., two in the bracket and two in the caliper) will be drilled to accommodate safety wire when the car is done. I plugged the two connectors into the ECU, applied 12V and depressed the supplied button for three seconds and everything worked beautifully.
The parking brakes are done until the wire harness is made. The ECU is in a potted aluminum case so I have a lot of flexibility on where to locate it. There are two wiring approaches:
Standalone: Modify the parking brake (PB) harness and keep it independent. I would shorten the caliper-to-ECU wires and lengthen the button lead so that it reached the cockpit.
Integrated: Tie it into the MoTeC system:
Connect the PB switch to a MoTeC output on the tail Power Distribution Module (PDM).
Connect the status wire (i.e., the one that lights the parking brake LED) to a MoTeC input on the tail PDM.
Use a MoTeC CAN bus switch in the cockpit to control the brake. Their switches have three indicator LEDs (red, orange and green) so I’d configure all to be off when the parking brake is disengaged and for the red to be lit when it was engaged. While MoTeC is anything but a DIY system, this type of logic can be easily configured via their free Windows-based software.
If I have enough inputs and outputs available, I’ll for with the integrated approach.
External view
View from the engine compartment outwards
Top view