Water Injection...anybody running that?

[tastyratz]

dont forget too, that its much better to use water injection post intercooler, because as a heat exchanger your intercooler will function better having first dibs at the hot air because of temperature differentials from outside/inside IC.

[Munna]

Guys I have being reading a book called 21st century performance (author Julian Edgar. eiditor of autospeed). There is a full section in this book on water injection. one part of this is Boost pressure water injection. Which uses a SUE18A nozzle.

One end of the nozzle is connected to boost pressure, and the other to a Pressurised water tank (ie Radiator header tank).

The nozzle is to be placed before the compressor wheel so it can be compressed with the air. The amount of water injected depends on the boost pressure so while off boost no water is needed a water ball valve is used to ajust how much water is sprayed.

This sounds like a good cheap system to prevent detination, Has anyone set up a similar system to this?

[Munna]

Found a link to this on the autospeed site

http://www.autospeed.com.au/cms/article.html?&A=0115

[GTRgeoff]

Guys I have being reading a book called 21st century performance (author Julian Edgar. eiditor of autospeed). There is a full section in this book on water injection. one part of this is Boost pressure water injection. Which uses a SUE18A nozzle.

One end of the nozzle is connected to boost pressure, and the other to a Pressurised water tank (ie Radiator header tank).

The nozzle is to be placed before the compressor wheel so it can be compressed with the air. The amount of water injected depends on the boost pressure so while off boost no water is needed a water ball valve is used to ajust how much water is sprayed.

This sounds like a good cheap system to prevent detination, Has anyone set up a similar system to this?

This appeared to be a good system however discussions I had with Aero development engineers revealed that spraying the water in pre-turbo can have a very detrimental effect upon the life of the turbo compressor blades and their leading edge shape. Even worse on life was when they sprayed a jet (not atomised spray) directly into the compressor blades but the result was the same performance wise.

This is the reason I go with the mechanical pump system which is relatively cheap and simple to tune.

[Merli]

I've also read of negatives of boost-controlled water injection setups... I can't remember exactly what the problem was though

[GTRgeoff]

The pressure is relative to max boost, which is not much really compared to mechanical pumps (up to 30psi in most cases) and unless you run non return valves for an accumulator action from the boost supply the flow is variable which can cause dribbling and poor atomisation. You also need a water/air injector to blast atomise the water which are temperamental to [low] pressure. All systems will have pros and cons though and need careful thought.

[meshmesh]

Try this method of controlling water injection.. alot more controlled as it uses the AFM readings to determin spray..

[if the link doesn't work let me know as it may need membership]

http://www.autospeed.com/PTNR_www/cms/acce...l?buy=A&id=1539

PS: Geoff, I haven;t forgotten your offer, just got Nigel from ICE on my back saying NOWAY, DONT DO IT! So I see what he thinks next week when my mods get installed.

[tastyratz]

ive thought up of an idea the other day on how to run an excellent water injection system. alright, we all know what the benefits of water injection are; it lowers the cumbustion chamber temperature to help prevent detonation. water before the turbo WILL destroy your turbo like nothing, so its a good idea to run after intercooler setup due to also the fact that water will sit in the intercooler which is no good. what are the weaknesses of watercooling?:

1. it takes up valuable space, most of us which cannot afford to lose, making you either give up your windshield squirters, or relocate it to the trunk which in most cases equals...

2. poor response. the farther away it gets the less responsive the system gets, because most systems involve some sort of activation which activates the pump, which takes a second to get the water going which means boom if it takes too long.

3. different forms of activation.

4. leaking

what can be done to remedy this? thats all on a returnless system, but what about an always on returning system? heres my idea:

power the pump, which you can use just a fuel pump, by a relay into the stock fuel pump. when theres fuel pressure theres water pressure. you can run this pump out of a few gallon tank in your trunk now. run a line from the pump all the way under the car to the engine bay. over by the throttle body split the line with a "T" connector. on one end of the connector goes a open close solenoid, which is activated by a boost pressure switch. attach a pressure stop valve (i have no idea what they are called i just guessed but they go inline and wont let any fluid through unless there is x psi of pressure on the valve) after that is the aquamist nozzle (or whatever you choose) into your intake piping. one end complete now we go from the other end of the t. that line just runs all the way back into the water tank you built. now you have a constantly under pressure system that instantaneously responds because of that being what it is. this eliminates any lack of response and ensures a quick on water injection system. the pressure stop valve thing ensures that there will be no leaking of water when the car is powered off as a safety, and will also ensure that there will be absolutely no leaking of water during solenoid opening. theres also no problems on location because now you can easily put your water supply where it counts and is out of the way. the only problem ive come into is where and what kind of solenoid should be used in this setup? it cant be something too expensive, and preferable if anyone sees one can you give me a USA friendly part #? im not from aus.

[meshmesh]

have you tried these www.h20injection.com & www.h2oinjection.com

[tastyratz]

assembling your own kit not only ensures quality components, but it can be custom tailored to your own liking. you can build a 500$ setup for 1/3 the price. unless its computer controlled its not worth blowing all that money on a kit.

[GTRgeoff]

Try this method of controlling water injection.. alot more controlled as it uses the AFM readings to determin spray..

[if the link doesn't work let me know as it may need membership]

http://www.autospeed.com/PTNR_www/cms/acce...l?buy=A&id=1539

PS: Geoff, I haven;t forgotten your offer, just got Nigel from ICE on my back saying NOWAY, DONT DO IT! So I see what he thinks next week when my mods get installed.

He probably has valid reasons for not being too keen, such as 'What happens if you are running a hard tune and you forget to fill the water reservior?' or something goes wrong with the system.

Many guys are running good power without water, and usually because their build and tune are all good kit. Water will always add to the ability to produce more power in almost any situation, and is great if you are running a less than ideal setup as it will allow more power for low bucks, but ultimately the best bet is to build stronger and have an engine capable of more power than you want to use, as I have done now after the last failure (BE bearing).

I spent over $5K on the engine machining and other componentry and did all of the labour myself, effectively getting a $10K+ engine and setup, and will only occasionally run to 8500 redline and dial in more boost and advance for track racing, while the water is on. The rest of the time is kept realistic to save the engine and licence and let the little lady drive it sometimes.

[YRL05S]

The negatives of water injection far out weigh the positives. In short water does not compress, which can lead to hydraulic failure or bent rod(s). Just tune or build your motor properly, water injection is a bandaid solution. It was used in aircraft in world war 2 and that's where it should stay. It is a waste of time and money.

On a positive note the aquamist system is the best i've seen.

Edit : Can't spell, it's monday

[GTRgeoff]

I'll take this opportunity to disagree with you quite strongly on every point you have made except regards aquamist. As a mechanic and Engineer of very broad experience I am less prone to the blunt statements of "tuners" whose livelihoods rely upon reliability and repeatability, for good reason. Hence they will not be willing to work toward novel solutions.

Back up your statements with fact and experience or refute my own, if you have the knowledge. Otherwise you are just being negative without the education to make a difference and detracting from the thread.

As a known detonation suppressant, there is little to surpass highly atomised water which means that in almost every situation tuning on the edge of the particular systems abilities you will make more power. The issue is cost effectiveness for the power you wish to make, and the inconvenience involved.

In some cases it is a bandaid, or it can be a cost effective alternative, and there is also the combustion chamber cleaning aspect for long term operation.

No-one is suggesting stuffing a garden hose in the intake and turning it on so the incompressible nature of water is not of any concern if care is taken. Atomised oil is injested via the PCV valve and we don't wet our pants about that everyday even though it is also incompressible in large fluid volumes.

I hope you respond with something of value.

[meshmesh]

Before I start, my knowledge re WI is moderate at the least, but have spent some time researching the topic.

As I understand it, the "main" purpose for WI, is if you have or anticipate knocking because you either:

1. You plan to run higher boost than a standard FUEL tune will allow

2. Your using Low Octone fuel (91 as an exmple)

On the positive side, even if you DO &/or DONT have knocking issues as above, WI allows you to safely retard timing, cools your intake and allows you to run higher "power tunes/boost levels" than using standard pump fuels regardless of their octane level.

I had a discussion with a guy in US who has been involved with WI kits for a number of years with great success, about installing WI on the GTR. He felt it wasn't necessary for my particular set up, however did say that WI would still be a benefit either way. On the topic of spraying water over the intercooler he replied (quote) "it's like pissing on fan, & has no benefit".. I was a little confused by this & left it at that. The US are huge in WI kits, mainly because they have lower grade fuels (91 Octane)..

In short water does not compress, which can lead to hydraulic failure or bent rod(s).  

I thought this can only happen if "like geoff said" - you dump a huge amount of water/fuel ratio??

On a positive note the aquamist system is the best i've seen.

Do I sense a contradiction here?

On a final note, here's a link to a guy in the US who is infamously known as the King of WI. Many kits available today a based on his designs, and for the technical minded it's a fantastic read (spewing I didn't understand a word after the first sentance "hi my name is...").

http://members.cox.net/stevemonroe/AlcoholInjMod.html

[09ONE_32]

I am really interested in this subject, and am looking at setting up a system for myself, most likely methnol injection rather than water injection because of the better returns. I have been told on many occasions that people running a methnol injection system have dramatically reduced intake temps. I have seen pics where a N14 pulsar with an SR20DET conversion actually had condensation on the intake manifold, because it got so cold. Methnol also evaporates much much faster than water, so this is why the added cooling effect on the intake charge?

[GTRgeoff]

On the topic of spraying water over the intercooler he replied (quote) "it's like pissing on fan, & has no benefit".. I was a little confused by this & left it at that.

He's half right meshmesh, it is like pissing in a fan. The urine passed is at body core temp but when it hits the fan and is atomised and blown back you will cool off. definitely has benefit though for the right situations. Say for staging at the drags and you have a fan pulling air through the cooler.

Now if your intercooler or bank balance is marginal for application - say you want to do a few drag runs without a large outlay of cash - a water spray over the small cooler with a low thermal capacity to sink a lot of heat energy will allow you to run higher boost for longer.

My own data capture relating to this is significant in terms of the lower maximum temperature out of the cooler, the rapid temperature drop after a run and the lower than ambient starting temp, all contributing to a bit more boost and more advance = performance for almost no outlay.

Ultimately this is limited by the cooler flow capacity and the amount of water that can flow over it, but by then a number of other elements start to inhibit power increases so wholesale upgrades of exhaust and cooler as well as turbo may be necessary.

Putting an 800hp capacity Hybrid FMIC and temp logging was very enlightening. The sheer capacity of this big sucker to transfer heat out of the air charge is amazing. On a 26 deg day the temps went to 31 just cruising at low speed but on a power run they dropped rapidly to within 1 degree of ambient in a matter of seconds due to the increased air flow over the cooler. With water spray the initial temp is lower than ambient from the get go, but thus far has not been a problem.

[GTRgeoff]

I am really interested in this subject, and am looking at setting up a system for myself, most likely methnol injection rather than water injection because of the better returns. I have been told on many occasions that people running a methnol injection system have dramatically reduced intake temps. I have seen pics where a N14 pulsar with an SR20DET conversion actually had condensation on the intake manifold, because it got so cold. Methnol also evaporates much much faster than water, so this is why the added cooling effect on the intake charge?

While the cooling effect is welcome, and the alcy can add to the fuel charge somewhat, the presence of the atomised water is considered the major detonation suppressant. I am yet to see a truly convincing study into the cause of the phenomenon, but suspect it is closely related to the thermal capacity of water and the energy absorbed when it converts to steam in the combustion chamber (latent heat of evaporation).

If you do go alcohol, use isocol or denatured ethanol mix rather than straight ethanol water mix, as the website provided by meshmesh states, because the straight ethanol is a bit harsh on things it comes into contact with.

[tastyratz]

see i plan on running an rb25det in my 240sx over here in the states. i like the idea of keeping the 9:1 which makes it hard in the usa when running big boost. this is going to be a daily driver for me which probabbly wouldnt be taken to the limits at all points, but water injection is a very cheap alternative for me since i cant afford to be dumping massive amounts of tuluene in my tank every fill. if you guys want an intercooler sprayer or just cooler of sorts, it might be worth looking into the nitrous express Ntercooler system. this can run off of nitrous or co2. i have access to 92 and 93 octane gas over here ( r+m/2 method. im not sure how octane is figured there i heard it was different) the water will allow me to have a more "streetable" tune without compromising off boost driveability for my bigger boost. i for one have seen the effects of water when in large quantities, you can ask my 3 month old after install h22a swap sitting in the backyard with a hole in the side of the block as big as a soda can top. i found this out when it downpored a cold air intake doesnt agree with me. waters really nasty stuff, and right it doesnt compress as ive noticed. it does however yield big benefits. if you really want to learn more about water injection, the first place to hit up would be usa forums for owners of buick grand nationals. thats a car that will NOT take big boost without water injection, due to the way its designed i think after like (14??) psi water/ alky becomes almost mandatory.

[YRL05S]

Meshmesh, not a contradiction i was just suggesting that if you were to travel that path, i would suggest the aquamist unit as it is the best unit i have seen.

SkylineGeoff, i do have extensive experience with water injection, around 7 years worth. I experimented with making my own kit, which worked quick well in a high compression, naturally aspirated application. I also used that project to do research on octane levels and knock levels of various fuels aswell. This was with Mazda Motorsport in the late nineties. This is when we were developing the turbo kits for the MX5's after the SP program shut down.

These are opinions i was merely playing devils advocate and pointing out the worse possible scenario.

An instance i can remeber clearly is when the one valve in the feed lined collasped and as the car was parked on a hill overnight (i live in the mountains) the valve leaked water into the bore and in the morning, when the car kicked over the water did not compress and one rod was bent. Mazda's money no mine. This is a instance people need to be made aware of.

[GTRgeoff]

My own experiences with mazda BP NA engines revealed them to be a good stout engine, until I whacked a load of oxygen, extra fuel and water in and started to pull flat 7 second 0-100kmh runs with FWD.......then they start to hurt but my lab tests indicated not only higher BEP overall but also very much higher peak combustion pressures, almost like detonation with the oxygen injection although the spike appeared better controlled. (Hint: use an in cylinder pressure transducer)

Perhaps you didn't consider a failsafe location for the water injection back then??? It should be the number one priority.

As someone who may have developed a DIY water injection kit, how could you recommend going straight to the most expensive commercial kit available without sharing your experience??? You jump straight to devils advocate as a reason to shoot down other DIYers without qualifying yourself.....pretty unsharing.

So share your wisdom and experience....we're waiting.

Perhaps suggested volumetric flow rates vs capacity @ rpm and how to determine flow rate.

Maybe the types of spray nozzles used.

Where did you source your supply pressure and locate reservior?

How does water injection allow determination of RON and MON? Not something I have ever considered so I am interested in that.