Water-Meth Injection Q&A

[dlabonte]

Hello 3Si Members,

Water-Methanol Injection might be new for a number of you. The below write up is to help you get a beter understanding of what it is all about.
We hope that members of this forum find the below information related to water-methanol injection beneficial. If you have any questions please post them and we would be glad to help.

History:
First off water-methanol injection is nothing new. Water Injection was first successfully implemented in WWII on the P-47 “Thunderbolt”. The Turbo Charged Pratt & Whitney R-2800 engine normally produced 2000 HP, with water injection the engine could produce up to 3800 HP. With water injection, the P-47 had 20 minutes worth of high power output for combat situations. One initial problem was that at high altitudes the water would freeze. So to prevent freezing, methanol was finally added to the injection mixture. Later studies done by the Army Corp of Engines actually determined that with a 50/50 mix of water-methanol even more power could be produced over water injection alone.


On Demand Octane Boost:
Octane is simple a measure of a fuels ability to resist spontaneous combustion, also known as preignition. Due to high temperatures and pressures associated with forced induction, a fuel might ignite before the spark event. This results in a very fast flame and extreme combustion pressures that can destroy an engine. The higher the fuel octane, the slower the fuel will burn and less chance of preignition.
Engine knock is actually different then preignition. Knock is the result of the spontaneous combustion of left over gasses in the cylinder. The engine damaging effect is similar to preignition.

Higher octane will not make more horse power by itself. If an engine is tuned for 93 octane, and C116 race fuel is added to the tank, the engine will not make more power simply from the different fuel. If the engine is tuned for C116, then more power can be made, either by more spark advance or more boost. Problem with C116 is one, it is expensive, and two you are wasting that high octane fuel at idle or low engine loads when it is not needed.

The octane rating of water is infinite. It can’t spontaneously combust as you can’t burn water. Methanol is also a high octane fuel in itself. Here are some octane ratings of various fuels:

Chemical / RON / MON
(The octane number you see in the US is [RON + MON]/2)

Methanol / 133 / 105
Ethanol / 129 / 102
Isopropyl Alcohol / 118 /98
MTBE / 116 / 103
Toluene / 124 / 112
Meta Xylene / 164 / 124
Dicyclopentadiene / 229 /167

As a rule of thumb, 50/50 Water/Methanol injection will increase the octane rating of pump gas by 25% during injection. (Note that C16 Race gas is already 116 octane, W/M will slow flame more). So with a load based injection system, you only get the octane increase when needed.
Water is capable of cooling the combustion chamber more efficiently then gasoline. Water has a higher Latent Heat of Vaporization then gasoline. When water is injected in very small droplet sizes into the combustion chamber, it readily absorbs heat as the partials go from liquid to gas state. The water particles actually “pop” or create multiple micro explosions. These micro explosions help to slow the flame front, effectively increasing the octane rating. These micro explosions also help to “stir” the air fuel charge or create a swirl effect in the combustion chamber. This swirl effect results in a more complete combustion of the fuel, leading to lower NOx emissions. With a more complete combustion, engine knock is reduced. This is due to the lower amount of gases available after combustion that can spontaneously combust.


Air / Fuel Ratios:
A gasoline engine will make the most power at an A/F of 12 to 12.5 to 1. The problem is that at this lean of A/F ratio, a forced induction engine will have a tendency for preignition when using regular octane pump gas. That is why most forced inductions engines are tuned for an A/F of around 11.5/1. At 11.5/ 1, 10-15% extra fuel is being added to cool the cylinder and top of the piston to prevent preignition. This extra fuel is not burned in the combustion process and goes out the tail pipe.



A 50/50 mix of water-methanol, when injected in the right quantity, will lower A/F by at least ½ point. Now the engine fueling can be reduced, more timing added, or more boost can be added allowing the engine to make more power.
Chemical Intercooling:
Most water-methanol injection systems are designed to spray the injection mix after the intercooler and before the throttle body. These systems are designed to inject the mixture with a high pressure pump and fluid atomizing nozzle. The smaller the injection particles, the more surface area there is of the small droplets, and the more heat that can be removed. As mentioned above, the high Latent Heat of Vaporization of water lowers in the Intake Air Temp as the water absorbs heat going from a liquid to gas state. A cooler air charge reduces the chance of pre-ignition allowing for more timing or higher boost levels.
An intercooler does the same thing to lower air charge temperatures. One draw back of an intercooler is the boost pressure drop across the intercooler. A second is that in an air to air intercooler, cooling efficiency is limited to that of ambient air temperatures. A third draw back is cost and weight of large front mount intercoolers.


Injection Fluids:
The most common question we get is “Where can I buy Methanol”. Most are surprised to find out that everyday window washer fluid is nothing more then water and methanol.
When using window washer fluid for injection, look for these items to insure you have a good product.

• The fluid is Blue
• The label says protects to -20 or -25F
• No soap bubble form when you shack the bottle.

Note you want to avoid mixtures that contain propylene glycol (anti-freeze). This is commonly added to window washer fluid to lower the temperature rating and is harmful to the engine if injected.
Here are some methanol ratios of commonly available washer fluids per the manufactures MSDS.

[jay04]

good post

[1fstascar]

Awesome post, I gave ya some rep for it (not that you probably need it) definatly should be stickied.

[dlabonte]

Thanks for the rep. Always glad to try and answer any questions.

[ProwlerGT]

dlabonte - What led me to this sticky is I was researching the truth about electrolyzing water to save gas (better mpg) and to get more power hopefully. Obviously that method is different than what you wrote about here, but it would be nice to know if the "electrolyzing water" method to produce better MPG and power does work or not.

Having read your tech info here leads me to a few questions that I didn't see answered I suppose because you may feel some of these questions might result in speculation. Whatever though, people like to see numbers/ranges. In any case here goes:

Directly stated - What are the main benefits from water, meth or water-meth injection?

On a Naturally Aspirated engine with no computer ability to increase spark advance (assuming spark advance is solely controlled by the computer? wrong assumption?) and obviously with no ability to "boost" intake is Water-Meth injection a waste of time if I am looking for better MPG and more HP (again on a NA engine)?

Are Water-Meth injection kits really more for race cars than daily drivers?

Will Water-Meth injection yield better MPG in an NA? on a Forced Induction engine?

Will Water-Meth injection yield more power in an NA? on a Forced Induction engine?

What power increase (in percentage range) have you noticed for the 6G72 engines that your (or any) Water-Meth kits have been added to? or for any 6 cylinder engine?

What if one just wanted to use water and not methanol with your the injection kit? IE: I live in the south.

What happens when the water-meth container goes empty while driving?

Lastly not really for me, but for others regarding the chart:
What is NoX?
What is CO?
What is HC?

[ducky]

Very nice writeup indeed. I would also like to see the answers to the questions above...

[dlabonte]

The generation of hydrogen from water through electrolysis is about the most inefficient method to generate hydrogen. I have not tested any of these "canning jar" systems that are popping up on the net, but based on the physics behind it I would have to same scam. Very little hydrogen would be created and thus have little effect on engine performance IMHO.

Water absorbs a lot of heat out of the intake air charge. The octane of water is infinite as it cant burn. The water slows down the flame front in the combustion chamber which increases knock resistance. As the water "flashes" to steam helps create some additional in cylinder pressure leading to more torque. Combustion temps are cooler and EGTs go down. As the steam goes out the exhaust, you have more mass hitting the turbo, leading to faster spool up.

Methanol is a high octane cool burning fuel. Injected to partially replace the gasoline that you pull out from tuning and richens up A/F through more complete combustion burn.

We have a NA system used on a number of Corvettes. Usually gains are though leaning out motor and degrease in long term fuel trims. Just bolting it on an NA, will see some benefit from cooler intake air. but with a little tuning gains can be very good.

W/M systems can be used on daily drivers and are not limited to race car applications. Customers have installed our systems on everything from snowmobiles to diesel Freight liners.

W/M will allow for greater power gains in forced induction applications.

many of our customers run just straight water for intake cooling and some detonation control. For straight water, use one nozzle size smaller then recommended for application.

An empty tank will not damage the system. Based on how you are tuned we offer the Injection Fail Safe (IFS-10) It is a flow monitoring unit that can be used to limit boost in the event your w/m flow stops.

Lastly measure of harmful vehicle emissions
NOx - nitrogen oxides
CO - Carbon Monoxide
HC - Unburnt Hydrocarbons or soot.

Best regards,

Dan

[2xmks]

Very good read. Much thanks.

[dlabonte]

Glad you found the information helpful. Let me know if you need anything else.

Best regards,

Dan

[Kibwe Walker]

I will check around but where can you buy 100% methanol?

I would just rather mix it myself so I know for sure what I am getting.

Also the single plate nitrous induction found here Ultimate Performance - 3000gt / Stealth parts page

is that something you can use with your ISG-10 and VC-25D?