What about always injecting tiny amounts of NOS and thus to be able to lower the combustion temperatures and also increase the power of continually lean burn conditions in order to get fuel economy?

Can NOS be produced at home ?

Nope, no home production, but look into water injection, same idea of cooling the combustion temperatures. Allows you to advanced timing for more power and decrease fuel injected also. :-)

I've just litely read about water injection, sounds like a neat and difficult idea.

If this works out well though, why do we worry about water in the tank? especially in the small amounts that may get in there

Water in the tank messes up the fuel, but this water is basically misted into the air stream to make it more humid, so it doesn't fuss with the fuel as much, at least I'm thinking. Water injection isn't so hard, check out the article on it, ;-)

Water in the gas can be hard on fuel pumps and fuel injectors.

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Injecting small amounts of nitrous isn't going to get you anywhere. A proper nitrous system costs $450 plus another $100 for a good bottle heater. If the nitrous solenoid were to leak you would have leak of nitrous into your engine and over an amount of time your engine will be gone. The best uses for nitrous is at a track and with Intake and Header and electronics that cut the nitrous off right before your redline.

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Not to mention a lot of the serious racers will actually rebuild their engine after every race.

Well it depends. The only people I see that do that are running 7's in the 1/4 mile. Either that or some idiot injecting a huge shot into a stock engine. If the engine is 2 liters or smaller I wouldn't do any higher than a 55 shot. If it's like 1.5L I wouldn't do higher than 50 shot. For mine I used to do 75 shot, but it's a 2.4L

When you go to V-6 you can inject up to 200 shot safely, the higher the number the more stuff has to be upgraded. For 200 shot you'd have to have a 255 pump, fpr, make sure your A/F ratio is good, or have some controller.

If you're looking for better mpg do some wind diffuser stuff, pump up your tires, change your driving.

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I know water injection.

What does EGR do ?

Exhaust Gas Recirculation

Takes some of the unburnt fuel and runs it back through the intake manifold for cleaner emissions and better gas mileage.

And how does it provide "cleaner emissions" ?

Water reacts with Ethanol in gas to make a gel that will completely clog a fuel filter. This can happen casually from condensation, and any dry gas will start to disolve the gel. Water was added to Turbojets in the 50s. The idea was that at higher altitudes the water added density or an expandable substance, so there was more expansion inside the cylinder, when the mixture heated up. Think, if a liter(1 gram) of air will expand from to fill a 10 liter space when it's temperature is raised 1000f, and adding water(1gram) increases this to 20 liters, why not add water? I have a feeling that they encountered a corrosion problem with this.
I contacted a person at HESS and asked about a good starting place for info on gasoline additives and they suggested epa.gov. Here is a link with Reformulated Gasoline info. http://www.epa.gov/otaq/rfg.htm#Fact

Burning a bunch of crap that otherwise would be shot the heck out the tail pipe or not converted totally by the cat. Doesn't let as much stuff slip by, :-)

Much of the exhaust gases are burnt so they are inert.

Recirculated "burnt" gases to intake displaces some "fresh air" so that less fuel is injected by keeping the stoichometric ratio of 14.7:1.
And also this process is actually designed to "cool" the combustion chamber in order to prevent harmful NOx gases that occur under very high temperatures.
EGR works under part load conditions and somehow it is like converting a 2.0 liter engine to 1.6 when power is not needed at a particular rpm.

Highly elegant, known and used technology for:
- Keeping not to occur NOx gases.
- Fuel economy.
- Cooling the combustion chamber.


EGR does not work at idle and at WOT/maximum throttle situations.
So: Water injection should start when EGR is closed. which it is used in high performance cars.

However i am too planning to build a water injection system also to see how will it effect performance and fuel economy.

Did you guys have experience on making water injection by using "ultrasonic humidifiers" ?

Cool idea, and the only place that I've encountered them is in VERY large air conditioning systems for High Rise buildings, and in computer room HVAC systems. Evidently they are very energy efficient, very effective, and the amount of wate that is put into solution in the air, can be precisely controled.
Also if memory serves, they don't look like much more than the end of a pipe with a flang, so they would probably fit nicely through the plastic part of an air intake manifold. If the water was preheated to just below boiling, this would help solve the question of increasing the temperature of the intake air. Also it would help stop it from freezing in the winter. How do you drain it overnight, so that the water line doesn't freeze?

Definitely on winter some alcohol must be added in order to lower the freezing point of water.