Water Injection System

Estimated Modification Cost : $1000

Estimated Time of installation : 8 hours

 

Since day one, I've had a problem with detonation. After many feeble attempts to cure the problem. Water injection became the solution of choice. I installed the Carroll SC GEN IV system. The best location for suppressing detonation is injecting directly in to the intake manifold. So, I removed the adapter to have the bung welded to it. The other location to inject is before the compressor. Supposedly if you inject before the compressor, you can gain another 1/2 pound of boost because the water helps seal the compressor making it more efficient. 
Here's a shot of the bung after it was welded to the adapter. It makes for easy nozzle changes. Currently, I'm running a 10 GPH nozzle but I could probably reduce the size to gain a little extra power. I don't think it's worth the risk for a couple of extra ponies. Carroll SC has sizes ranging from 3 GPH up to 20 GPH in 1 GPH increments.
Here's a shot of the adapter back in place. Note that the nozzle is aimed directly into the opening in the intake manifold for maximum efficiency. 
When I had the bung welded on, I had to position it slightly forward on the adapter to clear the intake tubing. I have the system capped off here so I can drive the truck while I finish installing the rest of the system.
I mounted the MAP sensor on the fire wall in a convenient location to vacuum lines and the wiring harness which comes through the firewall next to the brake booster.

 
I decided against adding an additional reservoir to supply water for the system, so I removed the windshield washer reservoir and converted it into my water injection reservoir. You just have to watch it when you have your oil changed so the grease monkeys don't top it off with windshield washer fluid. It shouldn't cause any harm and you'll have a squeaky clean engine. I typically run a 60/40 mix of distilled water to denatured alcohol. You can get the alcohol at any hardware store.
I installed a grommet in the top of the reservoir on the side facing the front of the truck. This portion of the reservoir is deeper than the rest of the reservoir. I used a standard 1/4" rubber supply hose to feed the pump. Since this is a supply hose it doesn't have to be a high pressure hose. Al hoses after the pump need to be high pressure hoses.
I mounted the pump as close to the reservoir as possible. The pump is capable of self priming. The pump has a one-way valve on it's output which feeds a line attached to the blue pressure tank, water pressure switch and a solenoid. This allows the system to provide "instant" water injection. You are able to set the exact injection points without waiting for water to travel through the system. The solenoid should actually be positioned as close to the nozzle as possible to make the injection as instantaneous as possible. I didn't like having the blue tank mounted on my engine so I mounted it with the pump.

 
Here you can see the wiring nightmare. The harness is well laid out, but there's lot's of connections. I ended up shorting some of the wires and extending others. I mounted the controller under my dash with velcro. This allows me to change the injection points fairly easily. The controller has two injection set points. The first point starts injecting water at 50 psi and at stage two the pressure is increased to 100 psi.
Here's the final look of the installed nozzle and high pressure hose. Do not use anything but high pressure hose between the pump and the nozzle.
This picture shows the on-off switch and boost indicator. When the system is on and ready the amber light is on. The red LED mounted next to the switch indicates when the first set point has been tripped and the green light indicates that water is being injected. If the tank should run empty or water is not being injected for some reason, the red LED will still light once the set point is tripped, the green will not and then an alarm sounds.

I'm thinking about removing the potentiometers from the controller and mounting them so I can adjust the set-points from the dash. Just haven't had time to do it.