"Just add water". The once-famous advertising slogan gets new content. Bosch is constantly working to improve direct fuel injection systems. One of her new developments is engine water injection system.
In the last century, water injection into the engine has already been used on General Motors and Saab cars. But with the advent of an intercooler in the engine that cools the intake air, the need for a water injection system has disappeared. The system continues to be used in motorsport, but here it is not held in high esteem. In Formula 1 and WRC racing, the system is prohibited by regulation.
System water boost from Bosch opens a new page in the history of water injection in the engine. Most electronic fuel injection systems today are programmed to deliver extra fuel at high loads. Additional fuel (up to 20% of the total volume) is necessary to cool the combustion chamber and reduce the combustion temperature of the fuel-air mixture.
The WaterBoost system uses water instead of gasoline for cooling. Water actively cools the air-fuel mixture, thereby increasing resistance to knocking, earlier ignition and, ultimately, increased engine performance. According to the developer, the system of water injection into the engine increases engine power by 5%, reduces fuel consumption by 13%, and reduces carbon dioxide emissions by 4%. In general, everything is a plus.
The design of the water injection system includes a water tank, a water pump and water nozzles. Electronic control of water injection is carried out by the engine management system. A five-liter tank of distilled water is enough for 5,000 kilometers. But even if the water in the tank runs out, it will not cause harm to the engine. The motor will not develop maximum power and fuel consumption will increase. Do not worry about the possible freezing of water in the tank. As soon as the engine warms up the engine compartment, the water in the tank will melt.
The first automaker to bring the development of Bosch to implementation was BMW. Today, BMW is installing water injection on its M-series vehicles that provide safety in MotoGP racing. The water injection system is also being tested on the BMW 1 Series prototype.
The water injection system in the engine pumps water from the tank and sprays it into the intake manifold, which reduces the combustion temperature of the mixture by 25 ° C. This allows BMW to use an 11:1 compression ratio instead of the legal 9.5:1 ratio. Thanks to the higher compression ratio, fuel consumption is reduced by 8% and engine torque and power are increased by 10%.
The lower combustion temperature of the mixture reduces the load on
Maybe internal combustion engines are living out the last decades, but manufacturers are not giving up. They make the most of this technology by optimizing the engine design for efficiency and economy. An innovation recently reported by Nissan that invented the . Now Bosch has spoken about its achievements. The German firm introduced the WaterBoost water injection system for easy modification of existing internal combustion engines.
Even the most advanced internal combustion engine wastes about a fifth of the fuel. For example, it is spent on the engine cooling system. In modern engines, a little extra fuel is injected into the combustion chamber not for combustion, but for evaporation from the walls, due to which the engine is cooled.
Bosch proposes to modify the fuel injection system: use water instead of gasoline to cool the chamber. That is, the essence of WaterBoost technology lies in the fact that at high speeds a water pump is activated in the engine, which injects a little water into the combustion chamber shortly before igniting the fuel mixture.
Very little water is required: it takes several hundred milliliters per 100 km. Therefore, a small tank of water will need to be filled with distilled water every few thousand kilometers, which for most drivers will not become unprofitable. It's even nice: pouring water, you know that this water will be used instead of gasoline (when cooled).
And if the water in the tank runs out, it’s also okay, except that the torque will decrease slightly and fuel consumption will increase by a few percent.
As the Bosch experiments have shown, such a simple modification can reduce fuel consumption by several percent (up to 13%) without losing power and torque. Savings are possible when the engine overheats at the highest speeds: for example, when accelerating hard or driving on the highway at high speed.
In addition to saving gasoline, evaporating water also cools the engine better than evaporating gasoline.
As an added bonus to fuel economy, CO 2 emissions are reduced by 4%, making it easier for the engine to pass the stringent environmental regulations that modern gasoline engines require.
The most effective introduction of water injection will be for compact three- and four-cylinder engines. In other words, precisely for the engines used in today's most popular mid-size cars.
But that is not all. In addition to saving fuel, WaterBoost can add up to 5% more power to turbocharged engines. The fact is that the addition of water saturates the forced air from the turbine with oxygen and increases the burning rate of the mixture, allowing you to optimize the ignition timing - the angle of rotation of the crank from the moment at which voltage begins to be applied to the spark plug to breakdown the spark gap until the piston is at top dead center.
The idea of ignition advance is to ignite the combustible mixture in advance, before the piston reaches top dead center. With the correct choice of the ignition moment, the gas pressure reaches its maximum value approximately 10-12 degrees of rotation of the crankshaft after the piston passes the top dead center.
By changing the ignition timing and tweaking the firing timing, engineers can squeeze even more power out of powerful turbocharged engines, even in sports cars.
The first car to feature WaterBoost water injection technology will be the BMW M4 GTS with a six-cylinder turbo engine.
BMW M4 GTS. Photo: BMW Group
There is no information about the introduction of WaterBoost in cars of the middle price category yet.
Bosch has extensive experience in the automotive industry. It was Bosch who in 1887 invented a safe system for detonating the air-fuel mixture of an internal combustion engine from a magneto. This ignition system is still used in cars today. Prior to this invention, the mixture in the internal combustion engine was ignited through Daimler glow tubes with an open flame.
Bosch produces not only ignition systems, starters, but also many other automotive components. For example, it recently launched mass production of electric motors for racing karts.
Bosch electric motor for racing karts. Photo: Bosch
Electric motors are the future, but the internal combustion engine is not going to give up without a fight.
“Our water injection shows that combustion engines still have a few tricks left under the hood,” said Dr. Rolf Bulander, Chairman of Bosch Mobility Solutions and Member of the Board of Directors of Robert Bosch GmbH.
Fans of increasing power and speed have been interested in injecting water into the engine with their own hands in recent years quite strongly as a way to implement their plans. The acceleration of engines, their efficiency in the context of the rational use of the fuel mixture, engine cooling is increased.
As a result, by technically competently injecting water into a working mechanism in this way, it is possible to achieve specific results, and very good ones, in terms of environmental protection (but usually, the main task is still). In general, there are a lot of advantages - it remains to try to implement a tempting idea!
Do-it-yourself water injection into an engine is already attractive because not everyone has $ 2,000 (or even more) to buy a branded installation. In addition, a long time ago (back in the days of World War II, with high gas costs for military purposes), it was found that such a chip allows you to save up to 20% of fuel. At current prices, this is a significant factor! Yes, plus a significant part of the engine parts last longer than even intended by the designers. And an increase in afterburner by a third looks very tempting, even for novice drivers.
How the injection works
Theoretically, the design of the injection system is extremely simple: a water nozzle is made in the intake manifold, which sprays this liquid into the fuel mixture. Water in this system acts in two ways. Firstly, it cools the gasoline. And even from a school physics course, it is known that a maximum of 45% of the fuel is spent on providing power. The rest of the amount in our case, roughly speaking, we heat the street.
With such additional cooling, gasoline is already used by 70 percent. In parallel, instantly evaporating upon contact with hot cylinders and pistons, water in the form of steam creates an additional pushing force that pushes the piston more energetically.
By the way, the idea is by no means new.. It was comprehended and described by a certain Englishman Hopkins about a century ago. And World War II, as already mentioned, gave impetus to the active use of injection in aviation by both the Americans and the Germans.
Minuses
Attractive from several sides at once, the idea begins to cause some doubt when viewed from the other side. There are also disadvantages for engines with an injection system.
- Such engines often work somewhat unstable. This is especially evident at low speeds or when the throttle is wide open. Under such conditions, water is unevenly distributed over the cylinders, which prevents it from working normally;
- Do not forget that it is extremely unreasonable to pour ordinary tap water into the engine through injection. Yes, and bottled, purified, too. Such water will certainly contain salts, which, when the liquid evaporates, will begin to settle on the inner walls. Only distillate rolls - and it will take 2 liters for every 10 fuel;
- in winter driving a car with injection is quite difficult: the water will freeze. Up to a certain minus, you can fight this by adding methanol, but in most cases the injection has to be disconnected;
- Extreme care requires the tightness of the system.
Methods for constructing an injection system
Craftsmen have worked out two methods of injection:
- An additional washer tank can be used as a water reservoir. The liquid will be pumped with a conventional 12 V electric pump. As an adapter, a transparent thin tube is taken, for example, from a blood transfusion system, which is put on a needle from a syringe. She pierces the tube of the ignition timing regulator - it is rubber, it is not difficult to do this. The needle is fixed in a permanent position with sealant. Its thickness regulates the volume of water supplied;
- The washer reservoir can again be the source of the injection fluid. The capillary tube is led to a hole made at the bottom of the carburetor primary chamber through a jet. It is also made from a needle from a syringe. The principle of supply here is different: water is pushed into the engine through the use of vacuum. As a spray gun, in short.
Before proceeding directly to the topic of the article itself, I wanted to remind you that this is already part 4 and without reading the previous 3, it will not be entirely clear.
And so, BMW 330D E90 245 HP, 520 Nm - the declared characteristics of the manufacturer. In reality, this is how it is. Many tuner offices promise by recalibrating the native engine ECU up to 300 l / s and a torque of 600 Nm. I would really like to see a car with such indicators, which, after tuning, has already traveled a couple of tens of thousands of kilometers.
If we are talking about exactly the same engine, but on a BMW X6 30D, then I still believe, but not on a 3-series car. Yes, the motors are the same, but the cooling system is completely different, and this is precisely the weak point of the BMW 330D.
Power is needed not only on the graph obtained under ideal conditions, but also in more difficult ones. For example, on a hot summer day. I propose to look at the result of the measurement
Measurement in 4th gear, temperature 32 degrees and as a result 220 l / s, torque 528 NM. The main thing, as you remember from the posts about diesel engines, is the temperature of the EGT exhaust gases. In stock, on this motor, it reaches 730 degrees (see graph). Raising the torque on this machine safely is not a problem, but keeping it after 2800 rpm and not overheating the engine is not a software solution. As you can see on the graph, at 3000 rpm, the power from the wheels is 165 horsepower. I propose to see live how the power changes at this point while holding for only 15 seconds,
Power from 185 forces drops to 160 l / s, engine temperature reaches 112 degrees, EGT is more than 700. The engine control program is very smart, it will not let the engine die so easily, but as a result, power will be very, very cut off. Sorry - this is stock, you can imagine what will happen with the tuning "firmware".
And so, the problem is indicated, it's time to move on to simple solutions. For this, a water injection system was installed. In the first test, water was progressively supplied with a maximum value of 100 grams/minute. Just 100 milliliters per minute of ordinary H2O water. Looking at the result
232 l / s, torque 531 Nm, the maximum EGT value was 685 degrees. Yes, now there is a large reserve for increasing power in safe mode.
The result speaks for itself - 242 l / s and a moment of 544 Nm. The EGT temperature at the peak was 704 degrees.
A small theoretical digression. The supply of water, in addition to cooling the incoming air, significantly lowers the temperature in the combustion chamber and EGT. In test 2, the EGT temperature, although significantly lower than in the stock variant, is still higher than in test 1, where the water supply was only 100 ml/min. The reason is that the engine ECU has recognized that the temperatures of the coolant, engine, catalyst, etc. not so great and added fuel himself. Or rather, stopped making defensive adjustments.
As you remember, increasing the power on a diesel engine is very simple, just add fuel. And of course, it is even easier in this version to shorten the life of a diesel engine and turbine. To avoid problems, it is always necessary to find a balance between the power and temperatures of the internal combustion engine and EGT.
I propose to look again live, test at 3000 rpm, but with water injection
As you can see from the video, the power not only grew to 195 l / s from the wheels, but also lasted longer and at the end dropped to 172 l / s, and not as in the stock version to 160. The maximum EGT value was 680 degrees. The temperature of the motor, also at the peak, was 10 degrees lower (102 * C).
Moving on to test 3. Now we did not use water, but 50/50 water / methanol. Looking at the result
Methanol is already a fuel, and naturally contains energy, unlike just water. Accordingly, not only the power increased to 248 l / s and the torque amounted to 568 Nm, but the EGT temperature also rose significantly (740 * C).
Using methanol as a power booster for diesel engines doesn't seem like the right direction to me. Adding more than 50% methanol can lead to detonation, and indeed why, and isn’t it easier to simply increase the supply of native fuel through the classic “chip tuning“. But water injection opens up new possibilities and greatly expands the limits that limit the safe increase in torque and maximum power. The exception is winter time, when it is simply necessary to add at least 20% methanol to solve the problem of freezing water.
SUVs that climb mountains, mud, etc. experience severe stress on the engine due to cooling problems. The use of water injection radically solves this problem.
If there is interest, then in the next post, I will show you, using the example of the same BMW, the process of increasing power directly online and how much this task is simplified with the injection of a small amount of water. The goal is not to build a racing diesel car, but to safely, significantly improve the performance of a stock diesel engine and at the same time, refueling a small water barrel, doing no more than a standard refueling with very active driving.
I also offer a comparative chart, with all the above measurements
And the last thing I would like to say is positive about water injection systems (water / methanol). Oil, it has many functions, and one of them is the purification of internal combustion engines from various deposits. The water/methanol injection performs this function brilliantly, meaning your oil will last longer. Oil oxidation is the main reason that during engine operation, its parts and the lubrication system become contaminated with various kinds of carbon deposits. Lowering the engine temperature also has a very positive effect on the engine oil oxidation process.
Among other things, soot, deposits (carbon deposit) in the engine significantly impair the performance of the motor. I give an example - after all the measurements, tests on BMW with water injection and water / methanol, and there were quite a lot of them, we made the last measurement at the end, again stock. I suggest to look at the result
The conditions remain the same. As they say - "think for yourself, decide for yourself."
For a large number of drivers, the simple operation of their car becomes boring over time. As a result, motorists decide to start tuning their "swallow". Someone is seriously interested in improving the body, and someone is modernizing the heart of the vehicle - the engine. Of course, there are a huge number of ways to improve the latter, but one of the most sophisticated and interesting is the injection of water into the engine.
Naturally, you tell me, who in their right mind and sober memory will pour water into the engine, because there will be a water hammer, and it will fail? We hasten to upset you, such tuning is effective and safe. Let's take a closer look at the principle of water injection into the engine and even how to do it yourself.
How does it work
First, let's get acquainted with the interesting history of the emergence of such a phenomenon as water injection into the engine. About 110 years ago, a certain scientist-engineer by the name of Bychnki from Hungary began to pour water into engines, which were primitive at that time.
For a long time this question was procrastinated, but it never developed. Only 3-4 decades later, the English scientist Hopkinson began to seriously deal with this topic. He did some research on standard engines for the time. The results were pretty good, of course, the reduction in detonation was a priority, not an increase in power, but you can see for yourself how it turned out.
However, the one who actually developed and patented the injection of water into the internal combustion engine was Harry Ricardo. On this occasion, he even wrote a book called "High-Speed Internal Combustion Engine".
At that time, due to the large number of armed conflicts (40s of the XX century), injection was used especially widely in aviation. But with the advent of jet engines, this technology became uninteresting. Years later, in the 80s, motorists remembered injection and began to use it as a tuning tool that helps increase car power and speed.
But now, having met those who really helped the restylers, we can talk about the nature of water injection into the engine. It should be noted that not only water is injected into the internal combustion engine, but its mixture with methyl alcohol.
Experiments have established the optimal ratio, which was 50 to 50%. The principle of operation of the injection is simple: in parallel with the fuel-air mixture, an aqueous solution is also sent to the cylinders, but what does it give? It gives the following:
- Water, due to its high heat capacity, significantly reduces the temperature in the engine, thereby increasing efficiency. Why so? Remembering physics, you can easily understand this. In short, during standard operation, 40-45% of the energy from fuel combustion is used to make the car move, the rest "heats" the environment. Injection, by reducing the temperature inside the cylinders, allows you to increase the efficiency of the engine up to 70%, since it is much easier to compress cooler gas and the energy spent on compression is significantly reduced.
- Also, the water in the motor allows you to drive more air into it, which increases the compression ratio.
- Of course, water is not poured “solidly” into the cylinders. It gets there in atomized form and, combining with gasoline, helps the fuel fill the entire space, so that it burns out evenly. This phenomenon provides an increase in efficiency, reduces detonation, and increases engine power by up to 20%.
Methyl alcohol in water assistants was chosen for a reason. It burns much more slowly than gasoline, increasing pressure build-up in the engine. But what happens after that, you know.
Important! The ideal ratio of water to air when injecting water into the engine is approximately 1/12 (+/- ½), in other proportions the fuel will not burn out completely. As a result, the muffler will “shoot”, and the engine can detonate from an excess of air.
Advantages and disadvantages of technology
No matter how common the type of tuning would be, it has its pros and cons. Water injection into the engine is no exception, so let's get acquainted with them in order to understand whether it is needed at all.
Advantages:
- increase in engine power up to 20%;
- reduction of fuel consumption up to 20%;
- increasing the efficiency of the mechanism and the clarity of its work, as a result of which the life of the motor increases (it has been checked more than once);
- significant reduction in the risk of detonation of the internal combustion engine;
- a significant benefit from the modernization of the engine system, yes, you will have to fork out for the installation (and even then not always), but how much will be saved on gasoline.
Flaws:
- it is important to install everything correctly, otherwise, with the slightest inaccuracies in the installation of the water injection system on small or fully open dampers, the engine will work unstably;
- dependence on the liquid necessary for injection, since you cannot fill in ordinary water, and you need about 2 liters of distillate per 10 liters of gasoline;
- in winter, injection operation can be compromised, because water can freeze, so you have to tinker with experiments in the proportions of methanol and water.
We make an injection with our own hands
The main negative consequences of water injection made by folk "craftsmen" is that these unfortunate restylers choose the amount of water supplied by "poke" and often make mistakes. As a result, the internal combustion engine receives a water hammer.
Important! In order not to classify yourself among such poor fellows, start supplying water (water mixtures) with the smallest possible quantities. Only by experimentation will you be able to choose the best amount of feed. The main thing you have to achieve is stable operation at all stages of the machine's acceleration.
Let's agree that you understand how to inject water is not worth it, and what must be taken into account. In this case, you can start tuning.
First of all, if finances allow you, it is better to purchase an already made water injection system into the engine. Yes, it costs a lot (from 40 + thousand rubles), but its installation is simple and, most importantly, correct operation is guaranteed.
But if you do not have money, you can do homemade products. Today we will tell you how to make water injection into an internal combustion engine with your own hands in three ways. The first two are presented below, and the third will be in the video, at the very end of the article.
First way:
- As a water tank, use a washer barrel from any car, the main thing is that it fits in size to the place where it will be installed. It is important to install a salt filter at the outlet of it so that excess “dirt” with water does not get into the engine.
- To continuously pump fluid into the engine, purchase a 12 volt electric pump.
- The main water movement is a thin, preferably transparent, tube.
- Also, a jet is selected experimentally at the end of this tube.
- The last two (pipe and jet) are water regulators, with their thickness and diameter you have to experiment.
- This entire system is brought to the manifolds connecting the injector (carburetor) to the cylinders, holes are made in them and everything is sealed. In rare cases, fluid can be fed directly into the engine by making holes in it.
Second way:
- It is done in the same way as in the previous method, a washing tank and a supply tube.
- The tube is brought to the hole from the bottom of the carburetor (primary) chamber using a jet.
- The principle of operation of such a system is aimed at vacuum. You can also use other "discharger" devices by connecting the system directly to the engine.
Important! Regardless of the choice of method, it is important to achieve a clear and correct dosing of the liquid. Water injection into an injection engine is practically no different from injection into a carburetor - the main thing is to set up the system.
There are also heavier systems for self-construction, their main meaning is to add nozzles to the intake manifolds behind the injector (carburetor), which are connected to the fluid pumping mechanisms.
