[Supra Bob]

Water injection is used on Forced induction cars (i.e. blowers or turbo's) to do a few things. What it does it spray a very fine mist of water (or water alcohol mixture) into the intake charge prior to it entering the combustion chamber. The two main effects this has is that it increases the effective octaine raiting of the fuel (atomized water and/or alcohol will burn, but relatively at a very slow, controlled rate) and decreasing the intake charge temperature (which will also make the fuel charge less likely to detonate under high compression conditions). I know of a few Grand National/Regal T-type guys who run 20 pounds of boost with no Intercooler and a water injection system, and it works well for them. There is a point of diminishing returns with these systems, and there are dangers of using them as well, but a properly set up and used system will work wonders.

Using a water injection system will not give you more Horsepower by itself, nor will it increase your gas mileage, as thats not its intention nor design.

 

[Supra Bob]

Who told you water will burn? I assure you this is not the case! What it does is flash into steam, thus absorbing latent heat from its surroundings.

The point of water injection is to reduce combustion chamber temperatures, which allows you to run more boost/compression/ignition advance. It does not increase the octane of the fuel, but it has a similar effect. If you tune your engine accordingly you can see worthwhile gains, but I doubt it would be worth it on a NA 5M-GE unless it was heavily modified.

A nice side-effect of water injection is it keeps you pistons and combustion chambers squeaky-clean; it effectively steam-cleans the engine's internals every time you use it!

If set up properly, a portion of the water WILL burn. The reason being is that water is made up of Hydrogen and oxygen (which I know you already know), and both of these burn VERY well (again, as I am sure you know.) Certain water injection systems are set up in such a way that some of the water or water alcohol is sprayed so fine that it is indeed possible to burn the mix... tho this is more on the Alcohol systems... guess I shoulda been more specific on that.

As for the Octaine... the water mixed into the fuel and air charge makes the charge less prone to detonation as water controls the burn rate of the fuel and (as you said) lowers the intake charge temp... god damit.. I know this isn't coming out clear... let me repost later tonight before I take my pain killers again.

 

[Supra Bob]

>steps out of the drug induced haze for a few minutes and begins to wonder how to pull is foot out of his mouth<

Ok..I think what I was trying to get at was the Alcohol would burn in the mix... or something to that effect.

How about I just shut the hell up for now and enjoy my pain killers?

::beats his head into the wall for refuting thermal dynamic laws...::

 

[Supra Bob]

Dave, the dangers of these systems are really minimal, and theres a few comercial ones out... NX put the first one out (they call it the N-tercooler, or something similar). Any source of CO2 will work. The one I am building I am using an NOS selenoid and firing switch to fire it, and am using a 20 oz bottle from a paintball gun for the CO2... MUCh cheaper to refill that way than a fire exstinguisher.