Its really not that hard at all...just tap into like 4 wires into your ignition harness. The plug and play harness only helps for the basic 3/4 wires in your ignition harness. If your turbo timer has any other special features (o2, parking brake sensor, ect.), they need to be wired in seperately.
Here is a write-up on the hardwire in a 1g, hope that helps.
Turbo Timer Hardwire in a 1GB