I just wanted to show how I routed the wiring for my boost gauge in the engine compartment. I tapped into the diverter valve pressure line like everyone else.
(1) Mount the pressure sensor on the existing bracket on the driver's side shock tower. The bracket conveniently has the perfect size hole for the HKS pressure sensor I used.
(2) Route the wires from the pressure sensor to the ECU compartment on the passenger side using the wiring conduit tray. The tray conveniently has an unused wire harness routing path.
(3) Create a hole in one of the rubber boots for the wire harness to penetrate into the ECU compartment. You can put a little silicone on this to seal it up.
(4) Locate the electronics for the boost gauge in the ECU compartment.
(5) Route the wiring from the electronics unit into the cabin via the bottom hole in the ECU compartment that everyone routes their PROcede USB cable through.
(6) Tap into constant power (color = XXXX) and ignition (color = YYYYYY).
(7) I mounted my boost gauge in my glove box.