I don't follow you. Can you be more specific?

 

I have to assume your question is related to just adding water injection to a standard factory car?


Water injection's sole purpose is for cooling - nothing more nothing less. This is the very point that has sparked many arguments over the internet discussion groups for years, I am sorry to say that the concept has never been fully exploited and understood.

A factory-produced engine will run perfectly and produce good power and clean emissions without injecting water or alcohol. This is a valid statement and not many will dispute it. But it will only hold true if the environment is ideal. Taking a normal engine to work in an extreme hot ambient conditions and high payload, the engine will suffer from all sorts of performance losses due to the in-build selfb protection mode. The ECU will first retard the ignition when the sensors detected high air temperatures, high water temperatures and knock - this first line of defense work well in the short term. But if the condition persisted, the engine will inject extra fuel for cooling purposes.

When you come to the turbo and supercharged engines, the engine will suffer twice as much stress then those previously stated. Further more, if the engine in question is being turboed or supercharged by a third party bolt-on kit offered on the market without any in-build self-protection provision, you are really asking for big trouble. Some aftermarket kits do offer intercooler or some form of fuel enrichment device to supplementing the original injector - don't forget that the extra fuel from the original in-built "fuel dumping strategy" has already been used up to fuel the extra air provided by the force induction system.

As you have already mentioned that one should not tune the engine beyond the knock threshold or unnecessary timing retard - if this is the case - water injection has no place in this type of tuning method. Why not just buy a factory made turbo car and just leave it alone - no tuning is required. Water injection is for those who want to venture further, much further than just put a rising rate fuel regulator and turn the boost up and few pounds. Sooner or later, your knock threshold will be reached again, by then you are firing the engine at TDC and run an air fuel ratio of 9:1 and the size of the intercooler measure 6 feet by 12 feet. Then come a point that matter what you do, you have arrived at the final barrier...

Water, with its huge latent heat property can now be used effectively to enable you reclaim you timing loss and run correct air/fuel ratio and at the same time keeps the engine cool without bored washing and increase cylinder wall wear.

Some mentioning of water displacement of O2 inside the combustion chamber and loss of oxygen will result. Consider this, dumping six-times more fuel to achieve the same cooling effect as water will also alter your air/fuel to such and extent that it will no longer burn properly, more power will be lost. Which method displaces more O2?

Combustion temperature (EGT) should be kept between 850- 900C for cast pistons and 950-975 for forged pistons with injection. Injecting water is for lowering the destructive combustion temperatures (EGT: 900c upwards) - it is a common mistake and often mis-interpreted as bad for power production, used by many anti-water injection tuners. There is a place for water injection in the modern tuning world.

 

The Aquamist systems have varying levels of fault detection. I found that the System 2D has the best balance of system simplicity and richness of fault tolerance features. The 2D can be easily configured to trigger a relay upon a "water delivery fault". A water delivery fault includes low fluid level, no fluid, pump failure or a clog at any point in the plumbing. Once a fault triggers a relay the signal can be used to drop boost, or depending on the sophistication of your engine management, switch maps & drop boost.

As far as plug-n-play, I'm not certain the Aquamist qualifies in that regard. It's not terribly complicated to wire but it does require installation of quite a few individual components. The WORKS/Aquamist system based on the 2D looks to be plug-n-play but as far as I know it has never been offered for sale.

 

Richard, welcome to the boards. You've been a great help and your wealth of knowledge has been greatly appreciated with my Aquamist set up.

 

Thanks for your post. I will need all the help I can summon here as I know very little about the EVO engine.

It is true that it is difficult to tell the the presence of alcohol in water.
I fail to understand how the Subaru and Evo can pass the CARB test wheb the factory car runs so rich ?

Have recently been playing with pre-turbo injection, made a pair of water jet holders for a skyline that stuck at the maximum power of the turbos. Tried running 3 bar boost from the previous 2 bar boost and have lost 70 WHP!!! I think the heat killed the power or the turbo have gone into the choke area. I hope the precooler will stretch the power further.

I like to ask you this, the heated air induced by the turbo's compressor wheel, is it purely through surface friction? Just like the re-entry of the space ship.

No sure how it works but your explaination sounded logical enough. I have yet to experiment how how water is need, I will start with our smallest water jet - 0.3mm. It flows about 75cc/min per jet.

I will progressively phase in the WI with the system2d - mirrorring the duty cycle of the fuel injector. Keep my fingers crossed. I will post the results on the WI forum. If anyone here is intersted, I will also post here.

 

This is one of my concernes. I will ensure the jet is pointed into the centre of the compressor wheel - aiming at the nut. This minimise tip wear.

Thank you for joining in. I am not sure what kind of comparison wirth shurflo pump, if the pressure is the same and stable, it will make little differences?

 

propellerhead has explained one way of achieving it via our system2d. But if you are running a third party system (non aquamist), a DDS3 flow monitoring gauge will allow you to detect water flow and cut your boost.

 

May I have a bit more information on this?

 

Heat is just kinetic energy. The compressor wheel accellerates the air giving it kinetic energy. However, in a moving fluid, it's generally not best to bring up pressure or heat because both vary significantly in different directions relative to the flow. When most people think of heat or pressure they are thinking of static heat or pressure. (Heat is kinetic energy and pressure is momentum. Thus, heat increases exponentially with particulate velocity and pressure linearly.)

Anyway, as I said the heat primarily just comes from the particles being accellerated. Then the outward motion is diffused into random motion in the diffuser scroll. That's when most people would say the motion was "turned into heat", even though that isn't entirely accurate because the total kinetic energy hasn't changed.

Also the "wet compression" helps mainly because most of the water evaporates inside the diffuser scroll. Since the sole purpose of the diffuser (or an intercooler, for that matter) is to "slow down" the particles of air, the water helps it do this more efficiently by absorbing much of the particle's kinetic energy. (Lack of kinetic energy keeps your beer cold too! )

If some of the water evaporates inside the compressor itself, most of the energy imparted into the water in the evaporative process should come from the random componant of motion of the air particles being flung outwards by the compressor blades. That should help draw more air in because the static componant of pressure in the reverse direction would be very low.

Anyway, that's just how I understand it; if anyone knows better, feel free to chime in.

-Adrian

 

My previous question about not wanting to run higher boost pressures. I mean, that most of the people here who run alchy injection crank the boost up to around 25-27psi.

I'm looking to run something with my normal pump gas tune, but get a little extra kick. I'm betting that straight water injection is the best thing for me, but I'm curious to see what you say.

I would think water injection or windshield washer injection, any pointers?

 

The engine's output is more or less restricted by the fuel octane. In order for the manufacturers to make claimed power based on pump fuel, they have to raise the boost beyond the knock limit of the normal fuel. (power makes sales)

Higher boost pressure is normally achieved by running a relatively rich mixture to lower the combustion temperature so the onset of detonation is less likely. This method is effective but not very fuel efficient. Most people don't really mind on spending more on fuel since this practice is pretty normal form the last 100 years.

However, there is something not often mentioned. Rich fuel mixture always produces carbon monoxide at the exhaust pipe. The richer the mixture becomes, the higher the carbon mionoxide concentration. Many engine tuning dynos still reads CO concentration to predict a/f ratio and the method is very reliable. Wide band lambda sensor has more or less taking over this task. The new trend has put more emphasis on the word "lambda" rather than "CO" percentage. it seems to have a cleaner image somehow.

An engine only inhales 20% of oxygen and 80 percent of nitrogen. After combustion, 80% nitrogen comes straight back out of the exhast pipe plus an equal share of carbon diodes and water vopour. The much treasured oxygen (20%) must be used wisely and should not be sqander out of the exhaust in the form of CO - a partially oxided carbon molecule only produces 30% energy of Carbon Dioxide. This is the very reason why power output is always lower when an overrich mixture is being employed as a coolant.

Replacing the excess fuel by water is a positive step forward to recovering some of the power loss through rich a/f ratio. If you can tune your engine and use water as a coolant, you can gain power without upping your boost at all. Other aspect of water injection may be discussed later on if this thread continues to attract interest.

We probably need some experienced WI users to chime in to confirm this claim. Words are useless unless we have facts to support it - I am not the right person to submit these facts.

 

I saw that you guys made some good power on an untuned and stock SRT-4 (18hp I think).

Do you think I can get equally nice numbers with my evo? I have basic bolt ons and tuning done though.

I know that you can't predict numbers, but just wondering how beneficial you think this would be.

 

Chrysler has done something quite unique on their SRT-4 compared to other performance car makers. They offer their own tuning package called "turbo toys". This plug and play dash panel allow users to dial in different boost level and ignition timing with dials and buttons. When the ECU sensed the setting programmed by the user is over- optimistic, it automatically cancels it, it flashes an dash led to tell the users their decision to "quit", reverts back to standard ignition setting.



This package is a godsend for SRT-4 owners, for a mere 1500 dollars, it includes a dash panel, 3-bar map sensor, set of high flow injectors and and a pair of intercooler spray bracket hosting four spray nozzles.

With such user-friendly package, it is possible to install an internal water injection system to replace the necessity of using high-octane fuel in the HOM mode (High octane mode -100+). After reading some of the post from the SRT-forum , I was presently surprised to learn that WI was able to sustain the hOM mode better than 100 octane fuel!

As you have mentioned, getting a 18 horses out of the SRT-4 is child's play. It is a pity that other manufacturers doesn't offer such a package, It appeared that the only way to take advantge of WI on your factory car is go to a tuning company, putting your trust that they know how to tune with WI, safely. Unfortunately, like any business, they would preferring to tune your car their way and sometimes WI is not on thier comfort list of options.

EVO, like many other turbo equipped cars, has some inbuilt intelligence on managing their ignition timing upon detection of knock. When WI injection is installed. the ECU will automatically advance ignition due to absence of knock and low inlet temperture readings. it will make gain with WI, but I cannot say how much - if you have some ways to lean off some fuel .... you will be there sooner than you think.

 

Hey Richard, it' me Joe. You've given me alot of good and informative advice through E-Mails these past years. Welcome. I thought I would try out your new thread. I would like to mention that Vishnu has introduced the S.M.A.R.T. system for their Xede piggy-back. It has alot of potential for optimizing a water/alcohol set up for our Evos. Here's a link to a Vishnu thread on the S.M.A.R.T. system: https://www.evolutionm.net/forums/showthread.php?t=142221. There's alot of reading to do, but you can see the potential. I myself have an Aquamist 2D set up and am still just scratching the surface of it's potential. I am using water along with alcohol as my mixture of choice. I believe along with the S.M.A.R.T./Xede and some serious tuning from Shiv, I will reach my goal for some strong performance on our terrible 91 octane premium gas in California. Here's a link to my water/alcohol injection installation on my 03 Evo for those who would like to check it out.
http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=654

 

Richard:There are 2 red wire from the FiA2, one to the HSV, the other to the non-switched side of the injector. Since they are both red, how do I tell which one goes where?

And the grey wire is connected to +12V? And on the 806-157 pressure switch, the activation of the injection occurs when the circuit is broken on the NC circuit?

What kind of seal material in used in the HSV; will it be good for 50/50 MeOH/water mixture? thank you!