DIY water alcohol injection setup!

[Jason]

I did a water/alcohol injection setup over the weekend with great results. Since I still dont have the manifold I want and a regular intercooler, some chemical intercooling was in order. I'm planning to take it to the track this week and its the last test and tune before the season is over. I had to do something!

The nice thing about this setup is that its boost sensative, as in the more boost you make the more it will flow. As boost drops off the flow does too, so your not stuck with a on/off only window that can be too much at a certain rpm or boost level and then not enough at another.

Parts needed:
bottle of some kind
small inection orfice (I used carb accel pump discharge nozzle)
Ebay cheapo boost controller
a few feet of windshield washer system hose or vac hose
fishtank one way valve
vac line "T" to tap into manifold pressure hose to injection pump
zip ties

I used a carb accel pump dump jet out of a Solex one barrel carb of a VW bug. I drilled the orfice to "60" (.6mm) and that has worked out to be a good size. I could probably size it up another .05, but I dont want to go too big and then have to get another one tio replace it. For me, the 60 made a noticable difference and there is no clatter when its running with it on. A nice side benefit besides the intercooling is that it will help clean your combustion chamber as the water turns to steam. Also, it really helps clean up the smoke! I went from a haze of smoke at 15lbs boost to absolutely nothing under full boost at WOT with the injection setup. Here are some pictures:




I positioned the orfice just ahead of the compressor wheel so the turbo can help atomize the water. Also, you may notice inline there is a one way valve for a fish tank. That keeps it from bleeding water into the intake when the water level is above the orfice. It is installed in the direction of flow, but provides just enough resistance with the little rubber flapper inside to keep it from bleeding. I've also incorperated a inline bost controller to regulate the boost level that the system starts to flow. Without it, you would drain your tank in no time as these cars run a couple to 5 lbs of boost on the highway. I have the system tuned to start to flow at around 8lbs off boost, so regular highway cruising there is no flow, but as soon as you lay into the throttle it begins to work. As the boost increases, so the does the pressure in the bottle and therefore the flow does as well.

Here is a diagram:

I used an old windshield washer bootle. You can use anything as long as it can be pressurized.

Jason