I made my own preturbo water injection similar to Rice's kit. I decided to do it this way to save money, while still having the reliability of running aux injection. I also wanted a simple design with very little to worry about in terms of failure. With a mechanical system you don't have to worry about pump failure and all the associated wiring, relays, and fuses. Just a pressure switch and solenoid. (if I could figure out a mechanical way to eliminate these 2 items I would)