if you could only have one, what would it be and why?
Im thinking about initially starting out with 5-6 psi of boost and once that is tuned, try 8. completely stock 318 tuned with MS. i really like that theres no tank to refill with an IC, but space is an issue because i have AC. i can get the blue windshield washer fluid at any local gas station, so its very easy to fill the water meth tank if i go that route. i also like the fact that WM cleans the motor of carbon build up on the pistons, combustion chamber valves ports ect. i would set it to turn on at 7psi of boost. so if you could just have one, what is the safer and more cost effective way to go?(i can only get 91 octane at the pumps)

i was reading this on another site:

To set-up a water injection system, you can use a fluid tank, small pump, and a Hobbs switch to inject fluid into the inlet tract. This switch closes at a specific pressure, and is installed in the intake manifold. One Hobbs switch is NAPA part# 7011577. This corresponds to a Hobbs part number #76052. It is a normally open 2 terminal switch, factory set to 15 psi. However it is adjustable from 14 psi to 24 psi. Both lower and higher pressure rangesare available from Hobbs 5000 series pressure switches.

An alternative is the Summit Racing “Oil Pressure Safety Switch”. It is made of steel and finished with zinc plating, for just $13. It opens at 7 psi (non-adjustable). Instead of being plumbed to the oil system, you can screw it into the manifold and use boost pressure to turn it on/off. Similar switches are available from Holley (PN 12-810, $20), and Mr. Gasket (MRG-7872, $13).

thx!