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post #18 of Old 10-24-2014 Thread Starter
Why so serious, Bro?
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How much water / methanol do I need to spray?

That would all depend on why you are spraying. If you are only using the water / methanol mixture for cooling, you can get away with spraying as little as 15% of your total fuel flow. This will reduce the temperature of the charge air and allow the ECU to take advantage of the higher octane which will result in a bit more power and much safer driving conditions. For forced induction or high compression modifications that are tuned to take advantage of the additional octane and cooling properties of the water/meth injection, you can spray as much as 25% of your total fuel flow depending on what your tune requires. Most water/meth injection kit manufacturers will have recommended spray values based on their kit.

What kind of fluid do I need to use?

There are several companies that sell premixed water methanol mixes. All use distilled water (water that has had all of the minerals filtered out <~~~ IMPORTANT) and purified methanol with no additives. The nice thing about using a premix is that you know that you are getting a precise mixture of water/methanol at a controlled ratio that is close to 50/50. With that said, you do not have to use the premix. Blue windshield washer fluid that is good to -20 degrees fahrenheit contains approximately 31% methanol and purified water. Some may have a small percentage of cleaning solution which you should try to avoid but will not be detrimental to your engine. HEET, a fuel drying product, is 99.5% methanol. Mix three bottles of HEET with your -20 degree windshield washer fluid and you have a 50/50 mixture of water / methanol that you can use in your injection system. You can also purchase methanol in bulk and use distilled water to mix your own; however, that is a bit more challenging and 100% pure methanol is flammable with a very low flashpoint. Not something you would probably want to store in bulk in your garage. WARNING: Do not use any windshield washer fluid that isn't blue. Also, if you find windshield washer fluid that goes below -20 degrees, make sure it does not contain ethylene glycol. Also, do NOT use E85 or ethanol fuels in your tank. In a pinch, you can use isopropyl alcohol (rubbing alcohol) or denatured alcohol, but both have lower energy by content and lower latent heat vaporization and will not be as effective as methanol.

Do I need to buy a kit or can I just make one on my own?

There are some very complicated equations that go into developing an efficient water/meth kit that would be difficult to duplicate on your own. First off, you will need a pump that can pressurize the fluid to at least 50 psi for proper atomization, specialize spray nozzles... again for proper atomization, and a control apparatice that controls how much fluid is sprayed and when. If you were to buy all the pieces parts separately you would end up spending far more than the price of a baseline water/meth kit.

How much heat will the water/meth mixture absorb?

Water/meth mixed at a 50/50 mixture sprayed at 15% of the fuel rate of flow will absorb between 50-150 degrees celsius (122-302 degrees fahrenheit) of heat depending on atmospheric conditions. When combined with your intercooler, this can reduce intake air temperatures from 0-10 degrees above ambient temperatures. You will never see temperatures below ambient air temps, but you can get as close to them as possible. Heat is an engine's enemy with regard to air charge. The higher the air temperature, the lower the potential energy of the air/fuel mixture and the greater the possibility of pre-detonation. Cooling the air charge as much as possible reduces the possibility of engine damage while also allowing you to unlock the full potential of your engine.

My car isnt knocking now, why do I care?

Safety, safety, safety. One tank of bad gas can destroy a tuned engine. If you want to limit the chances of pre-detonation, water/meth injection is the answer.

Is it better to inject the water/methanol solution before or after the Turbo? Where is the best place for my car?

There has been more discussion recently on the internet advocating pre-turbo injection. Most of the debate centers around increased atomization. You can probably get away with this in the short run if you inject a small quantity of finely atomized fluid (less than 10micron droplet) with a very low injection duty cycle. Also if you donít care about turbo longevity (like some race applications where the turbo is replaced frequently) or you have a system that doesnít atomize correctly and need the turbulence to help (low injection pressure and nozzles that arenít designed to atomize correctly). In diesels, especially where injection quantities are large in relation to fuel and where there is benefit to injecting at low/mid engine load states on up, it becomes a question of when compressor wheel damage becomes too severe as pre-turbo injection has been proven to cause compressor wheel erosion. The amount of erosion depends on the quantity injected, the size of the droplet injected, the speed of the compressor wheel, and the injection duty cycle (what % of total engine operation is water-methanol injected). Also, the argument of reduction in compressor work per unit flow and the increase in mass flow rate doesnít hold water in a properly sized modern non-wastegated turbo. For most applications on the Genesis Coupe, adding the injector right after the throttle body is the most effective location for the injector spray nozzle.

Can I install the injector nozzle before the intercooler?

You can but because the intercooler's design is to cool hot compressed air coming from the turbo, much of the water/meth mixture will be squeezed out during the cooling process and pool inside of your intercooler. YOu lose much of the cooling properties of the solution and water inside of your intercooler is a bad thing... don't do it.

Is there any benefit to spraying nitrous in addition to water/meth?

Nitrous Oxide increases the amount of oxygen available to the engine to create a bigger bang. It also provides a cooling effect much like the water/meth mixture does... so yes... adding nitrous oxide can increase the power significantly either by itself or if used in combination with water/meth. In fact, Snow Performance has an additive that can be added to their water/meth mixture that contains nitromethane which, when broken down by heat, adds oxygen to the combustion process.

Can I run water/meth without a tune?

Yes but you will not see much in the way of added power if you are already running 93 octane fuel. The ECU can compensate for higher octane fuels up to 93, but not higher. With water/meth injection you will typically see effective octane levels exceeding 100 octane but not usually higher than 115 octane depending on how much solution you are spraying and atmospheric conditions.
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