Deanzsyclone
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Alcohol Injection
Want to run 5-10 PSI more boost then you are now? Sure you do, unless of course you’re opposed to adding 50-100 hp to your car. With alcohol injection you can do just that, all while buying your gas from the pump. I’ve been a huge fan of alcohol injection for many years now. Personally, I don’t see why everyone isn’t running some type of supplemental injection nowadays. Not having to pay outrageous prices for race gas will pay for your kit within the first year. To give alcohol injection its proper recognition, we’ll need to discuss a few things first.
When I say alcohol, I am referring to the chemicals in that category as a whole, such as Methanol, Toluene, Benzene and Ethanol to name a few.
The octane to compression threshold or knock threshold is one of the most important things one can understand as a tuner. What I mean by this is actually quite simple to grasp, but often misunderstood. There are two terms used in explaining this, pre-ignition and detonation. You’ll see what I mean as we go on. Let us therefore look at the easier one of the two to explain and understand, pre-ignition.
The name itself is self explanatory. The fuel is being ignited before it should be, causing all sorts of trouble. To understand we must consider just what takes place. We’ll use the compression stroke as our starting point, assuming that up to that moment of time the engine has been running satisfactorily. That being said, we have the piston commencing travel up the cylinder bore, starting to compress the fuel ready for ignition by the spark at the plug. Depending on the ignition setting, the spark should occur at just the right time to allow the mixture to ignite, the resultant explosion being so timed that its force is applied to the piston just as it is ready to commence its downward stroke. If the explosion takes place too late, then the piston has already started to descend, so the force of the explosion is reduced since there is now so much more room so to speak in the chamber. On the other hand if it occurs too soon, the force of the explosion meets the piston on its way up the bore, trying to force it down, so power is lost and a general state of opposing forces exists. It is just this that makes it necessary to time the ignition setting to agree with the type of fuel in use so as to get the maximum effect, also to have an ignition system that will ignite as much of the mixture as possible in the very short time it has to do so. Detonation is when the piston is traveling upwards on the compression stroke. But instead of igniting when the spark plug fires, it ignites on its own. This happens because the pressure is so great inside the combustion chamber with the added boost that the temperature gets hot enough to ignite the fuel before the plug fires. This in turn creates a flame front that is trying to push the piston back down, when the crank and rod are trying to push it up. The result is usually a cracked ring land or worse. The point of detonation will be different on every motor as there are numerous things that come into play. The motor’s static compression, the spark plug type and material, the piston design as well carbon deposits on the piston and head can all affect the combustion process. Hence the need for every vehicle to be tuned differently.
I’m going to use 91 octane pump gas as an example since that seems to be the highest and most available nation wide. When adding a turbo or increasing the boost on a vehicle that is turbo charged from the factory, we are essentially increasing the compression of the motor. So what determines the amount of boost we can add before the motor goes pop? Here in lies the octane to compression threshold. If you add boost, you need to add fuel. That part is simple, more air requires more fuel. The entire theory on making more power is based around this ideal. So why can’t we just install huge fuel injectors and run 30 psi? Because every fuel has a point where it auto ignites and 91 octane reaches that limit far before we ever see that 30psi. The octane rating is a measure of that particular fuels resistance to auto ignition. The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions. There is another type of octane rating, called Motor Octane Number (MON) or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON. As an example, Toluene has a RON octane rating of 124 and a MON rating of 112, leading to a (R+M)/2 rating of 118. (R+M)/2 is how ordinary fuels are rated in the US. The correct name for the (RON+MON)/2 formula is the "anti-knock index”, and it remains the most important quality criteria for motorists.
With that in mind, we can look at the benefits of alcohol injection. The biggest reason alcohol injection is effective, is the increased octane it has over 91 pump gas. Let’s use Methanol as an example. Methanol (Meth) has a (MON) rating of 105. So when Meth is sprayed into the intake either before the throttle body or in a direct port system, it effectively raises the octane of fuel that is injected into the combustion chamber. Using what we just learned, we now know that more octane means we can run more boost. There are several very good chemicals that can be used for this. Methanol is definitely one of the more popular ones, but you can use Denatured Alcohol, rubbing alcohol, Ethanol, E85, Toluene or any of those mixed with water. Water in itself IS NOT a means to increase your octane. However, when injected into the motor, it evaporates upon entry into the combustion chamber effectively reducing the combustion temperatures by up to 300* F. I’ll go into water injection in more depth later so as not to confuse the two different types of tuning involved. The above listed chemicals all have different octane ratings, so each will require tuning if you change between fuels.
Before we can really get into tuning and the effects of the different chemicals we can choose from, we have to understand the various injection options available to us. There are literally tons of options available today, ranging from DIY setups consisting of a spray nozzle, pump, fuel line, pressure switch and reservoir all the way to $1000 setups that are closer to running a full standalone computer. It’s up to the individual what avenue they choose for themselves based on budget and power goals. I’ll explain the 3 most common setup’s used today and the tuning involved with each.
The first is a simple one stage injection setup. In my personal opinion, this is a great avenue for beginners to start with and it’s VERY easy to tune. Here are 2 basic kits.
As you can see it’s a very simple design made up of a pump, some jets for tuning and the necessary lines, relay, pressure switch and reservoir. The idea behind this as well as most other basic kits is to provide the user with a kit that is easy to install and tune yet functional and affordable. The tuning of a single stage kit is fairly straight forward. First you need to install the kit according to the instructions included with the kit at the time of purchase. If it’s a DIY setup, then you’re on your own as far as the install goes. Once you have your kit installed you can begin with the tuning process. Let’s start by using 8psi as your current max boost setting. Before we raise the boost at all, we need to set the turn on point “on set” for the pump. This is done via adjusting the pressure switch or knob on the controller depending on the kit. These switches are adjustable via screw, knob or nut in most cases. How they work is simple. They have a constant power of 12vdc hooked to them, as well as a vacuum line from the intake manifold. Once the manifold pressure reaches a certain pressure, the switch will send that 12vdc to the pump. In order to figure out the “on set” point, other then trial and error, you need a vacuum pump. These can be purchased at any auto store such as AutoZone or Checker. The MityVac unit that I use is pictured to the right.
As you can see, it has a pressure gauge and trigger to increase the pressure output. Apply pressure to the vacuum line of the switch and see what the pressure is when the pump is triggered. Then adjust the switch to the required setting.
Want to run 5-10 PSI more boost then you are now? Sure you do, unless of course you’re opposed to adding 50-100 hp to your car. With alcohol injection you can do just that, all while buying your gas from the pump. I’ve been a huge fan of alcohol injection for many years now. Personally, I don’t see why everyone isn’t running some type of supplemental injection nowadays. Not having to pay outrageous prices for race gas will pay for your kit within the first year. To give alcohol injection its proper recognition, we’ll need to discuss a few things first.
When I say alcohol, I am referring to the chemicals in that category as a whole, such as Methanol, Toluene, Benzene and Ethanol to name a few.
The octane to compression threshold or knock threshold is one of the most important things one can understand as a tuner. What I mean by this is actually quite simple to grasp, but often misunderstood. There are two terms used in explaining this, pre-ignition and detonation. You’ll see what I mean as we go on. Let us therefore look at the easier one of the two to explain and understand, pre-ignition.
The name itself is self explanatory. The fuel is being ignited before it should be, causing all sorts of trouble. To understand we must consider just what takes place. We’ll use the compression stroke as our starting point, assuming that up to that moment of time the engine has been running satisfactorily. That being said, we have the piston commencing travel up the cylinder bore, starting to compress the fuel ready for ignition by the spark at the plug. Depending on the ignition setting, the spark should occur at just the right time to allow the mixture to ignite, the resultant explosion being so timed that its force is applied to the piston just as it is ready to commence its downward stroke. If the explosion takes place too late, then the piston has already started to descend, so the force of the explosion is reduced since there is now so much more room so to speak in the chamber. On the other hand if it occurs too soon, the force of the explosion meets the piston on its way up the bore, trying to force it down, so power is lost and a general state of opposing forces exists. It is just this that makes it necessary to time the ignition setting to agree with the type of fuel in use so as to get the maximum effect, also to have an ignition system that will ignite as much of the mixture as possible in the very short time it has to do so. Detonation is when the piston is traveling upwards on the compression stroke. But instead of igniting when the spark plug fires, it ignites on its own. This happens because the pressure is so great inside the combustion chamber with the added boost that the temperature gets hot enough to ignite the fuel before the plug fires. This in turn creates a flame front that is trying to push the piston back down, when the crank and rod are trying to push it up. The result is usually a cracked ring land or worse. The point of detonation will be different on every motor as there are numerous things that come into play. The motor’s static compression, the spark plug type and material, the piston design as well carbon deposits on the piston and head can all affect the combustion process. Hence the need for every vehicle to be tuned differently.
I’m going to use 91 octane pump gas as an example since that seems to be the highest and most available nation wide. When adding a turbo or increasing the boost on a vehicle that is turbo charged from the factory, we are essentially increasing the compression of the motor. So what determines the amount of boost we can add before the motor goes pop? Here in lies the octane to compression threshold. If you add boost, you need to add fuel. That part is simple, more air requires more fuel. The entire theory on making more power is based around this ideal. So why can’t we just install huge fuel injectors and run 30 psi? Because every fuel has a point where it auto ignites and 91 octane reaches that limit far before we ever see that 30psi. The octane rating is a measure of that particular fuels resistance to auto ignition. The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions. There is another type of octane rating, called Motor Octane Number (MON) or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON. As an example, Toluene has a RON octane rating of 124 and a MON rating of 112, leading to a (R+M)/2 rating of 118. (R+M)/2 is how ordinary fuels are rated in the US. The correct name for the (RON+MON)/2 formula is the "anti-knock index”, and it remains the most important quality criteria for motorists.
With that in mind, we can look at the benefits of alcohol injection. The biggest reason alcohol injection is effective, is the increased octane it has over 91 pump gas. Let’s use Methanol as an example. Methanol (Meth) has a (MON) rating of 105. So when Meth is sprayed into the intake either before the throttle body or in a direct port system, it effectively raises the octane of fuel that is injected into the combustion chamber. Using what we just learned, we now know that more octane means we can run more boost. There are several very good chemicals that can be used for this. Methanol is definitely one of the more popular ones, but you can use Denatured Alcohol, rubbing alcohol, Ethanol, E85, Toluene or any of those mixed with water. Water in itself IS NOT a means to increase your octane. However, when injected into the motor, it evaporates upon entry into the combustion chamber effectively reducing the combustion temperatures by up to 300* F. I’ll go into water injection in more depth later so as not to confuse the two different types of tuning involved. The above listed chemicals all have different octane ratings, so each will require tuning if you change between fuels.
Before we can really get into tuning and the effects of the different chemicals we can choose from, we have to understand the various injection options available to us. There are literally tons of options available today, ranging from DIY setups consisting of a spray nozzle, pump, fuel line, pressure switch and reservoir all the way to $1000 setups that are closer to running a full standalone computer. It’s up to the individual what avenue they choose for themselves based on budget and power goals. I’ll explain the 3 most common setup’s used today and the tuning involved with each.
The first is a simple one stage injection setup. In my personal opinion, this is a great avenue for beginners to start with and it’s VERY easy to tune. Here are 2 basic kits.
As you can see it’s a very simple design made up of a pump, some jets for tuning and the necessary lines, relay, pressure switch and reservoir. The idea behind this as well as most other basic kits is to provide the user with a kit that is easy to install and tune yet functional and affordable. The tuning of a single stage kit is fairly straight forward. First you need to install the kit according to the instructions included with the kit at the time of purchase. If it’s a DIY setup, then you’re on your own as far as the install goes. Once you have your kit installed you can begin with the tuning process. Let’s start by using 8psi as your current max boost setting. Before we raise the boost at all, we need to set the turn on point “on set” for the pump. This is done via adjusting the pressure switch or knob on the controller depending on the kit. These switches are adjustable via screw, knob or nut in most cases. How they work is simple. They have a constant power of 12vdc hooked to them, as well as a vacuum line from the intake manifold. Once the manifold pressure reaches a certain pressure, the switch will send that 12vdc to the pump. In order to figure out the “on set” point, other then trial and error, you need a vacuum pump. These can be purchased at any auto store such as AutoZone or Checker. The MityVac unit that I use is pictured to the right.
As you can see, it has a pressure gauge and trigger to increase the pressure output. Apply pressure to the vacuum line of the switch and see what the pressure is when the pump is triggered. Then adjust the switch to the required setting.
