The expansion port allows for options not supported by the factory harness such as sequential spark outputs, cam & crank triggers, nitrous control, stepper motor control, can bus & serial communication, etc. Complete list of functions is provided in the PiMPxs Startup Guide Table 2. 
-All wires have their function printed on the wire, and are color coded for ease of use. 
-Serial is for connecting to a 9 pin serial port on your laptop, a bluetooth or Wi-Fi adapter, or using a USB to Serial adapter cable for applications where the USB port on the side of the ECU isn't accessible. 
-VR shielded are for crank/cam trigger or speed sensors. 
CAN H & CAN L is for connecting to an CAN device like our All-In-One Gauge. 

***If you're wanting an assembled partial pigtail with less than 32 wires, select the connector, then select the appropriate wire and pin assemblies, and list what functions those wires are for so we can send the correct labeled wire for each function.
****Note VR wires are shielded pairs so each input requires one VR wire assembly from the list below.

Length: 8 ft 

Not for original PiMP