Where a mixture of water and methanol is injected into the intake of an internal combustion engine and is used to either cool off the intake air, add high octane fuel to the cylinder to control the burn, or a combination of the two.
See the source image
Reasons to install
There are several reasons that this is done and the most common is where a 50/50 mixture of methanol and distilled water is used in conjunction with advanced engine timing to get a gain in horsepower. This is achieved because the high-octane methanol prevents unwanted detonation, adds more combustible fuels to the cycle, as well as rapidly cooling off the intake air, reducing the chances for knocking or pre-detonation, two different events. [1]
Knocking, also known as detonation is where the fuel inside the combustion chamber ignites at the wrong time due to a hot spot inside the cylinder(s). Because it detonates at the wrong time, it can cause extreme stress to the mechanical components and damage or destroy them within seconds if severe enough. [1]
Cooling off the intake air is always wanted because one can add more fuel to get a more powerful ignition and therefore more power. This happens because for fuel to burn properly, it needs a proper mixture of air to fuel, commonly called the Air/Fuel ratio. This AF ratio is different for every type of fuel but essentially means how much air is needed to get a full combustion of every molecule of fuel. Because of the complexity of the different AF ratios a simplified scale was released called Lambda. Lambda is simple because with every single type of fuel, a perfect burn is 1.00, rich is less than 1.00 and lean is more than 1.00. [2]
The reason that this is so important is because the more air is able to be crammed into the cylinder, the more fuel can be added and therefore, more power. Lambda is crucial because while an engine is running, it is using fuel and if running lean, meaning that there is less fuel than the oxygen available the flame burns much hotter, whereas if the oxygen available within the cylinder is less than the fuel available it burns a little cooler and prevents (to a small extent) premature detonation. [1]
One way to cram more oxygen into the cylinders is to use a turbocharger or a supercharger. They both compress air into the engine to allow more fuel and much more power. The drawback to this is that according to the ideal gas law when air is compressed it heats up. Because it can heat up sometimes more than 100 degrees Fahrenheit higher than the ambient temperature it dramatically increases the chances of knocking or pre-detonation. [3,4]
The most common option available to cool off the compressed and hot intake air is to push it through an air to air intercooler to bring the temperatures back down. [5] [See picture above]
Installation
Water/Methanol, commonly referred to as just 'Meth', is one option to increase horsepower and is rather easy to install. As shown in the picture above, the liquid mixture is injected into the air stream after it has passed through the turbo and intercooler by an injector under high pressure. The injector injects the liquid, sometimes called boost-juice, in as fine as a mist as possible to disburse throughout the air stream as much as possible to evenly distribute to each cylinder as well as remove as much heat from the compressed air as possible before being burned.
The liquid starts out in a reservoir and goes through a low pressure tube or hose into a high pressure pump that is resistant to the caustic nature of Methanol and then through high pressure tube or hose, sometimes 1,000 psi rated, to a one way valve, to prevent siphoning of the liquid when not under pressure. Then onto the injector, which is really a mist maker, and into the intake.
Some applications use electronics to alert the driver that the liquid reservoir is running low to prevent the engine from being damaged while running under load without the protection of the mixture. The complexity of the system is limited only by how much one is willing to spend.
Need?
Is water/methanol injection really needed? It probably depends on the application. For some, they might not have enough room in their engine bay for an intercooler, which can be as large as 4 feet wide and 2 feet tall or as small as 6 inches tall and 12 inches long. In this case, they would most benefit from having the water/methanol injection as far from the throttle body as possible so that the liquid mist can absorb as much heat as possible in as much time as possible. It may even be beneficial to only use distilled water in this case because water has a higher specific heat, meaning that it takes more energy to heat up the Water than Methanol, Ethanol, or even Isopropyl Alcohol which are around half as absorbent as pure water. [6]
Water/ Methanol Injection
Where a mixture of water and methanol is injected into the intake of an internal combustion engine and is used to either cool off the intake air, add high octane fuel to the cylinder to control the burn, or a combination of the two.
Reasons to install
There are several reasons that this is done and the most common is where a 50/50 mixture of methanol and distilled water is used in conjunction with advanced engine timing to get a gain in horsepower. This is achieved because the high-octane methanol prevents unwanted detonation, adds more combustible fuels to the cycle, as well as rapidly cooling off the intake air, reducing the chances for knocking or pre-detonation, two different events. [1]
Knocking, also known as detonation is where the fuel inside the combustion chamber ignites at the wrong time due to a hot spot inside the cylinder(s). Because it detonates at the wrong time, it can cause extreme stress to the mechanical components and damage or destroy them within seconds if severe enough. [1]
Cooling off the intake air is always wanted because one can add more fuel to get a more powerful ignition and therefore more power. This happens because for fuel to burn properly, it needs a proper mixture of air to fuel, commonly called the Air/Fuel ratio. This AF ratio is different for every type of fuel but essentially means how much air is needed to get a full combustion of every molecule of fuel. Because of the complexity of the different AF ratios a simplified scale was released called Lambda. Lambda is simple because with every single type of fuel, a perfect burn is 1.00, rich is less than 1.00 and lean is more than 1.00. [2]
The reason that this is so important is because the more air is able to be crammed into the cylinder, the more fuel can be added and therefore, more power. Lambda is crucial because while an engine is running, it is using fuel and if running lean, meaning that there is less fuel than the oxygen available the flame burns much hotter, whereas if the oxygen available within the cylinder is less than the fuel available it burns a little cooler and prevents (to a small extent) premature detonation. [1]
One way to cram more oxygen into the cylinders is to use a turbocharger or a supercharger. They both compress air into the engine to allow more fuel and much more power. The drawback to this is that according to the ideal gas law when air is compressed it heats up. Because it can heat up sometimes more than 100 degrees Fahrenheit higher than the ambient temperature it dramatically increases the chances of knocking or pre-detonation. [3,4]
The most common option available to cool off the compressed and hot intake air is to push it through an air to air intercooler to bring the temperatures back down. [5] [See picture above]
Installation
Water/Methanol, commonly referred to as just 'Meth', is one option to increase horsepower and is rather easy to install. As shown in the picture above, the liquid mixture is injected into the air stream after it has passed through the turbo and intercooler by an injector under high pressure. The injector injects the liquid, sometimes called boost-juice, in as fine as a mist as possible to disburse throughout the air stream as much as possible to evenly distribute to each cylinder as well as remove as much heat from the compressed air as possible before being burned.
The liquid starts out in a reservoir and goes through a low pressure tube or hose into a high pressure pump that is resistant to the caustic nature of Methanol and then through high pressure tube or hose, sometimes 1,000 psi rated, to a one way valve, to prevent siphoning of the liquid when not under pressure. Then onto the injector, which is really a mist maker, and into the intake.
Some applications use electronics to alert the driver that the liquid reservoir is running low to prevent the engine from being damaged while running under load without the protection of the mixture. The complexity of the system is limited only by how much one is willing to spend.
Need?
Is water/methanol injection really needed? It probably depends on the application. For some, they might not have enough room in their engine bay for an intercooler, which can be as large as 4 feet wide and 2 feet tall or as small as 6 inches tall and 12 inches long. In this case, they would most benefit from having the water/methanol injection as far from the throttle body as possible so that the liquid mist can absorb as much heat as possible in as much time as possible. It may even be beneficial to only use distilled water in this case because water has a higher specific heat, meaning that it takes more energy to heat up the Water than Methanol, Ethanol, or even Isopropyl Alcohol which are around half as absorbent as pure water. [6]
External Links
1. https://en.wikipedia.org/wiki/Engine_knocking
2. https://en.wikipedia.org/wiki/Air%E2%80%93fuel_ratio
3. https://en.wikipedia.org/wiki/Turbocharger
4. https://en.wikipedia.org/wiki/Supercharger
5. https://en.wikipedia.org/wiki/Intercooler
6. https://en.wikipedia.org/wiki/Heat_capacity
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