How To Choose The Right Water Injection System?

With so many choices and options available, we understand it can be difficult to determine the right water injection system for your engine. One of the most common questions we receive from customers is "which water injection system should I get?"

To better help you understand and decide for yourself, it's important to first have a basic and accurate understanding of water methanol injection systems and what they do for your engine. A helpful introduction to read on water injection is our article "Knock, knock..who's there? Detonation" and "116 Octane With Water Methanol Injection" . Once you understand how a water injection system works and how an engine can benefit from it, choosing the right system becomes much easier. 

Water Injection Articles

One of your biggest decisions you'll have to make is whether to use a progressive water injection system or a non-progressive system. The best way for determining this is by evaluating several key factors about your vehicles engine and its use. After that, it's simply a matter of choosing a system with a tank configuration which best fits and supports your application. Listed below are several key factors which we use to determine which water injection system is right for each engine and application.

Factors for determining the right water methanol injection system are:

There are certainly other factors that may also be considered, however, knowing these key factors listed above will ultimately help you determine which water injection system is right for your application. Lets begin discussing each of these factors and why they matter.

Naturally Aspirated Or Force Inducted

For beginners, knowing whether the engine is naturally aspirated, nitrous injected or force inducted will let us know what type of application we are initially dealing with and the type of water methanol injection system we will be considering.

While we certainly receive quite a few inquiries daily concerning the use of water injection on naturally aspirated applications. Many of these inquiries are people who do not have a application which truly warrants its use or will benefit from using a water methanol injection system. 

NA users who would benefit from a water methanol injection system are:

For NA applications we offer both progressive (Stage 2) and non-progressive (Stage 1) systems. Our Stage 2 progressive systems, through the use of our digital electronic controller, allow users to pre-select both start and full points. Thereby, creating a range between these two points in which the water injection system will proportionally inject more or less fluid according to the input signal sent to controller. Inputs may vary from manifold vacuum, throttle position, mass air flow sensor, MAP sensor, rpm, etc. Allowing users to effectively cover any operating range of the engine and develop settings to best suit the engine's needs.

On the other hand, our Stage 1 systems are not a progressive variable flow but rather a fixed rate flow.  Instead of a progressive controller. These systems come with an adjustable vacuum switch. This allows users to pre-select their activation point based on a drop below a pre-selected vacuum point. When activated the system will spray the same continuous amount of fluid until the system is deactivated and returns to standby mode. Adjusting fluid flow (jetting) is regulated by interchangeable water injection nozzles. Users may also activate the system by using any of the following switches such as manually, full throttle switch, rpm  switch, etc.

Both Stage 1 and Stage 2 units are designed for use with EFI and carbureted applications. Depending on the application (EFI or carbureted) and the type of water methanol injection system being used. The use of additional hardware such as a throttle position switch or full throttle switch may be necessary depending on users requirements. We offer these system's in both fender/firewall mount and trunk/bed mount versions.

Click the link below for our naturally aspirated water injection systems.

Naturally Aspirated Water Injection System

Nitrous Oxide Injection

Water methanol injection is quickly becoming the most effective, economical and efficient method for optimizing the performance of both wet and dry nitrous oxide systems. For nitrous applications, our Stage 1 systems are essentially all that are needed. The use of a progressive controller is generally not necessary as the water injection kit will be integrated into the nitrous system and will be activated and controlled by the same means. Our Stage one systems are easily integrated into both wet and dry systems and are designed to be triggered at the same time with your nitrous. Depending on your preference and application and available space, systems are available in both fender/firewall mount and trunk mount versions. Click here to view our nitrous water injection systems.

Benefits Include:

To read more about the benefits of water methanol injection with nitrous oxide click on the lick below.

Optimize Your Nitrous System With Water Injection

Type Supercharger Or Turbocharger Being Used

Knowing the type of supercharger or turbocharger helps us determine the following information

When dealing with forced induction applications, it's important to know the type of supercharger or turbocharger being used. While this alone will not determine the type of water methanol injection system to be used, it gives us a better understanding of the engine and its needs. Helping us better determine what type of system should be used.

Since not all superchargers and turbochargers build boost in the same fashion. Knowing what type of compressor is being used is important as it helps us determine how quickly manifold pressure (boost) rises in relation to engine load and rpm. This also then helps us determine the type of input signal to be used with the water injection kit to achieve our desired effects from the system. 
 
For example, centrifugal superchargers like the popular ProCharger, Paxton and Vortech supercharger do not begin to build boost until approximately 2500-3000 rpm while under a load. After which point boost will continue to rise linearly, increasing as engine rpm increases, reaching peak boost at peak engine rpm. When working with progressive and non-progressive water injection systems a simple mechanical boost signal is all that is needed.

In contrast, when working with positive displacement superchargers such as twin screw and roots styles superchargers by Eaton, Kenne Bell, Magnacharger, Whipple, etc,. Since these superchargers come into full boost almost immediately. When using a progressive type water injection system you do not want to use a mechanical boost signal as the input to the controller as boost will peg out almost immediately limiting the water injection controller from effectively covering the entire operating range of the engine. For EFI applications a MAF (mass air flow) sensor is the preferred signal to use with these applications. If not available, then either a RPM or TPS signal may also be used.

Additionally, knowing the type of supercharger or turbocharger helps us determine the type of heat being created by the compressor and understandably the type of intake air-charge temperatures (IAT's) we are working with. Furthermore, we have found that different compressors require more or less jetting. For example, twins screws and roots style superchargers with the water injection placed before the compressor require nearly one and a half times the jetting as do centrifugals and turbochargers at the same horsepower and boost levels. This is largely due to the injection being sprayed through the unit, the vast surface area of the rotors and due to the added heat they create vs. centrifugals and turbochargers.

the system starts injecting when the boost switch reaches the user-adjustable point and it injects a fixed amount of fluid through the nozzle until the switch opens again. This makes it a good choice for low to medium boost setups looking for an octane enhancement and cooler intake charge. Activation can also be set up through any other user-chosen switch, such as a full throttle switch, etc.

Both Stage 1 and stage 2 systems are suitable at this point. Due to the nature of these supercharger and how quickly they build boost. When using a Stage 2 progressive style system, it's best to use a mass air or MAP sensor output signal to base the water methanol injection start and full points off of. 

Intercooled Or Non-Intercooled?

Intercooled or non-intercooled helps us determine the following information

When dealing with forced induction applications. It's important to know whether the engine is intercooled or not. Knowing whether the engine is intercooled or non-intercooled, in addition to other factors such as how much boost and the type of compressor being used, lets us determine the type of air charge temperatures we are working with. Knowing the air charge temperatures is extremely important as it can easily tell us the engines urgency for additional air charge cooling and in combination with other factors helping us determine the severity for which detonation may or will occur and when an octane enhancement is required to help prevent it.

While this alone, knowing whether the engine is intercooled or non-intercooled, won't determine the type of water injection system to be used. This does play a major role, in combination with other factors, in helping us determine if a progressive or non-progressive water injection system will be need to effectively support the engine and provide it with the additional added air charge cooling and octane enhancement required to prevent detonation and achieve the performance we want from the engine.  

Even though further substantial reductions in air charge temperatures are obtainable by adding a  water methanol injection system to an already intercooled application. When equipped with an intercooler the need for a progressive water injection system is less urgent as an air charge cooling medium is already in effect. However, this by no means suggests that a progressive style system is not needed. Other factors must still be considered such as the engines compression ratio, iron heads or aluminum, camshaft, type fuel being used etc. As these also play an important role in determining if the engine may still require a progressive system to prevent the early onset of detonation and to effectively cover a wide range of engine load

Ultimately it is the severity for which detonation will or may occur that we must determine and if a progressive system will be needed to effectively support the engine and prevent the onset of it.

Lastly, knowing whether the application is intercooled or non-intercooled gives you a better perspective on possible nozzle locations and nozzle sizing required to achieve our desired results. For more information about where to locate the water methanol injection nozzle or nozzles see our article "Where Do I Position My Water Methanol Injection Nozzles"

Engines Current Level Of Boost

Knowing the engines current level of boost help us determine the following information

Ahhh boost. Probably the most talked about subject when it comes to superchargers and turbochargers.

Having now determined the type of supercharger or turbocharger being used and whether it's intercooled or non-intercooled. Our next factor to be evaluated is simply how much boost the supercharger or turbocharger is producing. By knowing how much boost is being produced, along with the two previously mentioned factors(type compressor and intercooled or non-intercooled), this begins to give us a very clear picture of the type of air charge temperatures we are working with. Additionally, knowing how much boost is being produced lets us know if were dealing with a narrow or wide range of boost.

While other additional key related factors will need to be considered, such as compression and type gas being used, which will both be address next. Knowing the amount of boost and the type of air charge temperatures we are working with begins to give us a very clear indication of the level of severity for which detonation can or will occur with the given engine. Thereby, allowing us to determine the engines urgency for an added octane enhancement as well as air charge cooling. In turn helping us then decide whether a progressive or non-progressive style water methanol injection system will need to be used to effectively support this engines needs. 

Additionally, knowing how much boost is being produced lets us know if were dealing with a narrow or wide range of boost. Thereby, helping us determine if a progressive or non-progressive water methanol injection system is needed to effectively support the engine.

For example, with low boost (4-6 psi) supercharged and turbocharged intercooled applications, generally all that is needed is a Stage 1 non-progressive type system.

As an application such as this will generally not need or benefit from an the added octane enhancement in the lower rpm range. Additionally, while this application is already intercooled and only running a low amount of boost. Depending on the type supercharger of turbocharger used and intercooler. Monitoring air charge temperatures after the intercooler will reveal a fair amount of heat above ambient is still in the air charge. By combining a water methanol injection system with an intercooled system we can achieve the lowest air charge temperatures thereby removing all the additional heat from the compressor leaving you only with a cool pressurized air charge. 

The level of severity for which detonation may occur is not great.

Aside from running to lean of an air/fuel mixture. Heat is the biggest culprit leading to detonation and engine failure with supercharged and turbocharged engines. It's not boost which damages engines but rather the heat associated with boost. The two most popular ways of reducing detonation is by reducing the air charge temperatures and raising the octane level of the fuel being used. This is why water methanol injection has become so popular. Unlike OEM and aftermarket street intercoolers, a water methanol injection will not only reduce air charge temperatures as good or better then an intercooler. It also acts as a substantial octane enhancer thereby effectively raising the octane of 87-93 octane by 15-20 points.  

Engines Current Compression Ratio

Knowing the engines current compression ratio help us determine the following

Just about every automotive performance enthusiast understands engines with higher compression ratios require higher octane fuels. Whether your running a naturally aspirated, forced inducted or nitrous injected gasoline engine. Knowing the engines compression ratio is one of the most important factors when choosing a fuel.

When it comes to building safe reliable detonation free horsepower, Octane is one of the most critical factors. If too low of an octane fuel is used, the engine will experience detonation/pre-ignition. Depending on how severe this detonation or preignition is and the type of internal components used. The damage can occur either instantly or slowly over time if left untreated.

Fortunately, as bad as detonation is. It can easily be avoided with the addition of a simple water injection system. Giving users a massive octane enhancement while providing additional charge air cooling to help prevent and eliminate detonation for occurring. Depending on the users need for an octane enhancement  

Ultimately it is the severity for which detonation will or may occur that we must determine and if a progressive system will be needed to effectively support the engine and prevent the onset of it.

Type Fuel Being Used Or Currently Required

Determining the type of fuel being used or currently required helps us determine the following information

Why does the type of fuel being used matter? Quite simply it's just an easy quick way to help gauge the engines current octane requirements and what type of fuel is currently required or being used to run the engine without detonation. Knowing this we can easily begin to tell if an engine needs a high octane racing fuel or if it can be ran on lower grade fuels such as pump gas before the addition of the water injection system.

However, keep in mind you can not entirely base the engines octane requirements simply by whatever it has in the gas tank. How the engine is tuned also needs to be considered as this plays a huge part in allowing the engine to run on lower grade fuels when a higher grade fuel should be used and is not.

For example, if timing is being severely retarded in order to run the engine on a lower grade fuel without detonation. Then the need for an octane enhancement is much more critical then one would have initial thought before examining the tune. I

By looking at both, the type of gasoline being used and the tune, we can essentially get an accurate indication of the engines current octane requirements needed to safely run without detonation. From there depending on the customer and any changes they may make to the engine or fuel type, in addition to adding the water injection system, would  need to be considered before choosing a system.

For example, if the users engine was running and required a high octane racing fuel prior to adding the water injection and now with the addition of the water injection system, the user is wanting to switch to a lower grade fuel such as pump gas. Then the use of a progressive type system is more then likely required in order to effectively support the engine and its need for an octane enhancement throughout it‘s entire operating range.

On the contrary, if the user wants to add the water methanol injection system in addition to a high octane fuel and is only looking for an added octane enchantment on the top end. A stage 1 type system is all that is need to achieve this.

Basically, if the need for an octane enhancement is urgent and is required early and throughout the engines operating range. Then the use of a progressive system is required to effectively support the engine. If an octane enhancement is only needed on the top end. A stage 1 non-progressive system is generally all that is required and sufficient. 

Engines Current Tune

Determining the engines current tune helps us determine the following information

By evaluating how the engine is currently tuned we can find out a lot about the engine and the type of performance improvements we can make by adding a water injection system and which type of system will best suit the engines needs.

One easy way to tell how an engine will benefit from a water methanol injection system is by looking at its current ignition timing and if ignition timing retard is currently being used to avoid detonation. If so, then right away we know by adding a water methanol injection system we can make significant improvements in the engines performance by simply adding the timing back which was being taken out to avoid detonation and in turn reducing the engines performance.

Another indicator we can look at it is the engines current air fuel ratio and if the engine is being ran excessively richer then ideal to help prevent the onset of detonation. While running an engine richer then ideal or optimal can help to reduce the onset of detonation. It also reduces the engines performance. With the addition of a water injection system users no longer need to run the engine excessively richer then ideal. Thereby, improving performance by allowing users to now run a more optimal air fuel ratio the before.

By looking at these two factors we can then determine the engines level of severity for which detonation may or will occur. This allows us to then determine if a stage 1 or stage 2 type system will be required to effectively support the engine and suppress the onset of detonation while also substantially raising the detonation threshold and not only allow us to make the desired changes in the tune to improve the engine performance but also allowing the engine to safely run more boost then previously without the water injection.

Type Driving/Application

Determining the type of driving/application helps us determine the following information

Understanding the type of application the engine and vehicle will be used for. I.E. street, towing, drag racing, road racing marine use, etc can be very important as it will also help determine the type of water methanol injection system is needed to best support the vehicles engine and application.

For Example, if the vehicle is to be used strictly for drag racing, A simple stage 1 type system is generally all that is needed for most applications. The need for a progressive system isn't as  necessary as the engine will be operating through a very narrow rpm range and engine load (essentially full throttle) during the entire race. Additionally, drag racers may choose to use a rear trunk mount system vs. a fender mount to keep additional weight of the front end. 

On the other hand. For example, applications which are to be used for road racing, A stage 2 type system is generally preferred over a stage 1 type system. The need for a progressive system is more urgent and generally necessary in order to effectively and seamlessly support the engine through out its wide operating range it will be ran during the race.

Another example would be turbo diesel applications in which the user is wanting to reduce EGT's. If it's our goal to target and reduce EGT's we can employ a stage 2 type system which can base the injection entirely off of EGT's. Allowing the users to pre-select start and full points based on EGT's alone.

Additionally, depending on the application and its use we need to ensure the size of the water injection tank is at least large enough to support the application. Surely smaller containers can be used for drag racing and users can simply refill the container every run if need be. While road racers will certainly need to have a much larger container considering their races will last anywhere between 20-30+ minutes.

Space Available On Vehicle

Determining the space available on the vehicle helps us determine the following information

Finally, at last we need to determine where on the vehicle we have space available to mount the water injection kit and its larger system components such as the water injection pump and tank. With today's vehicles it's becoming increasingly harder and harder to find space under the hood to mount the water injection pump let alone an additional tank.

When space isn't available for an additional tank. Users may consider using the vehicles existing windshield wiper fluid container for the water methanol injection tank. However, this may compromise the use of the windshield washer fluid function and require disabling the factory pump to prevent from spraying the water methanol solution on the vehicles exterior and paint.

When space is available for an additional tank often times the use of a very small container is all that is allowed. Thereby, requiring more frequent refills then one would have with a larger water injection tank. Additionally, depending on the vehicle, under the hood installations will generally require up to 4-6 hours to complete. 

When space isn't available under the hood to mount the water injection kit. We offer a rear trunk mount system as another option. This system relocates everything; pump, tank and electronics, to the rear of the vehicle. Advantages of the rear trunk mount system vs the under the hood system are.

Furthermore, just as important or more important for many is what will aesthetically look the best. Should the water injection system be mounted under the hood exposed or would we prefer it to be completely hidden and out of sight. While certainly many cars do have the space to install a small container and pump under their hood. This can be unsightly to some and take away from the car's appearance under the hood while also letting others know that you have it.