Water or Water/Methanol Injection DIY

[06YarisRS]

More building

I feel that the reliability should be good, but this is a little 'hack' looking, I suppose. The system should be hidden fairly as I want to remain as stock looking as possible.





Surprisingly, the tank tap adapter abomination is very solid. Of course, in 24 hours, I'll know if it holds water. I had to angle the barb in toward the car as those pesky fog lights encroach into the plumbing area.



Because I was too cheap to spring for a internally-bypassed pump, I had to rig up a return line with ball valve. I actually like this because I can adjust the pressure to the misting nozzles. There will be a pressure gauge installed next to the throttle body injector.



Return to tank



Water solenoid. I would have liked to installed this closer to the pre-throttle body injector, but it would have been very difficult finding a spot to mount it. The supply line runs pretty much vertical so there should be no siphoning. Like every part of my build, any hoses, tubes, pipes, lines or wire loom that come in contact with each other or any part of the chassis or engine get a ziptied piece of split hose between them to eliminate chafing.



When researching, I came across discussion of hydrolocking when using water or water methanol injection. These situations usually occured when there were system failures and rarely when the engine was running. In most cases, water gravity fed into the cylinders and hydrolocked the engines. Because my injection points are much higher than the highest water level, I can't see any issues. Also, my injector feeding the engine can produce max 100 cc/ minute divided into 4 cylinders. Even if the system stuck on during driving, it would take around 50 ccs of water to hydrolock one cylinder in one cycle. Also, I expect that there would be serious driveability issues related to quenched combustion before any hydrolocking could occur.