I have been doing a little research on water injection and came across the Spearco Water Injection system that doesn't require a pump. Boost pressure from the intake manifold pressurizes the tank and it can be set for different pressures by turning a switch on the unit (from as little as 2 lbs up to 8 lbs).
Does anyone have any experience or information on this system?
I'm really intrigued by a unit that doesn't have the possibility of pump failure. and the wireing certainly looks less involved than the AquaMist.
Granted the unit only holds .4 gallons which they claim will last a tank of gas.

I thought the Spearco WI system had a pump. Got a link to where it doesn't? I've been told that the pump and nozzles aren't very good but have no first hand knowledge of the system.

The link below is from Top End Performance.
http://www.racetep.com/wik.html#trbh20

It's a pre-turbo injection system however. Those generally cause small pitting on the compressor blades. Aquamist is a post-turbo system.

Since the ideal place is usually immediately after the IC, water injection is best used as a post-turbo setup.

Could work for you though, and it is waaaay cheaper. But I often wonder why one couldn't just modify some diesel injectors. Very high PSI, perfect atomization, already programmed flow rates. Probably just too darned expensive!

Adrian~

Probably because fuel injectors aren't usually very good at handling water.

For about $250 + some effort you can build your own a reliable system. Let see:

80 for the surflow pump
50 for hose and wiring
20 for hardware
30 for pressure/system on off switches
30 for aquamist nozzel
40 for misc parts

Even if you buy a kit, you still have to figure out the installation. Might as well build your own.

Probably because fuel injectors aren't usually very good at handling water.

That's why they'd have to be modified. :P I just meant that Diesel Injectors are tough, reliable, and powerful. Everything that most aftermarket water injectors are not, and exactly what they need to be!

Might cost more to properly modify them, but if it's at all feasible it could be worth the effort. Dunno though. Sometime I'll have to try it if I have the spare cash.

Adrian~

Well, I was thinking more about corrosion. I'm not sure how you'd modify them to handle that. And there's lots of good affordable water nozzles out there, although perhaps their long-term reliability in this environment is debatable. The hard part is finding a cheap, reliably fast water/alcohol safe solenoid and the equipment to control it - which is why most setups are constant flow. No matter how you attack the problem, I do think it makes a lot more sense to just assemble the "kit" DIY. There's plenty of parts lists out there..

Normal standard aquamist nozzel are very reliable, so are home depot water nozzel. I have been using aquamist nozzel for over 3 years and it never clogged once. Now I use only drinking water and that helps. There is no need to modify a fuel injector nozzel for water injection. Using a fuel injector also raise the issue of mounting fitment and location.

Aquamist pumps have a working pressure of 100psi to properly disperse the water, that coupled with the high-speed valve is what makes the aquamist system so reliable, and their jets are the best. Shurflo pumps flow 60psi, and if you're running 20 psi of boost you only have 40psi left to disperse the water, that's not enough.
On pre-turbo water injection, there is NO documentation that it pits the vanes on a turbo or causes any problems, and many people have been running low pressure water injection pre-turbo for years-imagine the cooling effect of water mist through the turbo! The one time I heard of water injection pitting pre-turbo was on a modified car that did not use an air filter!!!!!!! So that doesn't count.

Kent

OK, I just want to make sure I'm following this issue correctly. First, where would the nozzle be mounted in the "pre-turbo" system, in the air intake hose or in the intake hose off the IC? As apposed to mounting it over the IC or into the throttle body in the post-turbo? Spearco's placement scematic is a bit cryptic. Second, why would the "pre-turbo" system require less volume/psi than the "post-turbo" system? I understand the turbo compresses air and thus creates a denser more volumatic charge entering the combustion chamber, but does it require such a significant higher amount of water/alcohol post-turbo? If that is the case how could a pre-turbo system produce anywhere near the same results as a post-turbo system. Aren't the physics the same regardless; volume of air to voulme of water/alcohol to diplace/soak heat? Sorry if these are dumb questions, but I guess my mind isn't grasping all the issues. Also, how could the "pre-turbo" cause pitting of the compressor blades? The water is hitting the blades at hypersonic speeds and thus the impact is damageing them? While plauseable, it doesn't seem very likely, otherwise no jet turbine engine could ever fly in the rain (yes, I know they are different) but the principle illustration still aplies.

FYI, it's not true to say that the shurflo pumps only pump 60psi. They have pumps that do 60psi, and also pumps that do 100psi or 150psi, all very affordable. They're adjustable to meet a variety of flow needs, too. I'm also not sure why 40psi is "not enough" to properly atomize the fluid. Fuel injectors do just fine at that pressure. It all depends on the nozzle you're using. Just to set the record straight :-)

drwrx: The problem with pre-turbo water injection is the same as with draw-through carburetion. The fluid has too many places to stop and hang out on the way to the cylinders (and it's lazy, so it will try to do so), so it's difficult to determine a reliable volume to inject. You can certainly get away with it, and many people have and do, it's just not optimal.

I'd think the pressure would have to be more to atomize water depending on how large of a nozzle is used and how much boost is run. If you're running 20psi of boost and 40psi of water pressure behind the solenoid it's like having 20psi of pressure(not to point out the obvious). A good test(imo) would be to run 20psi and turn the solenoid on at the lowest duty cycle you will use and see how well the nozzle sprays. I ended up spending about $400 + the cost of a boost controller since I'm using the utecs boost map to control the idc of the solenoid. Would have cost at least $150 less without the aquamist hsv........blah. If I had to do it all over, I'd probably get the aquamist 2c kit. It's more then worth it imo since everything they make seems to be of the highest quality and small at the same time.

peace

"On pre-turbo water injection, there is NO documentation that it pits the vanes on a turbo or causes any problems, and many people have been running low pressure water injection pre-turbo for years-imagine the cooling effect of water mist through the turbo! The one time I heard of water injection pitting pre-turbo was on a modified car that did not use an air filter!!!!!!! So that doesn't count."

Actually old Saab 99's had a pre-turbo water injection system from the factory. They always came back with pitted compressor wheels, and they certainly ran air-filters! It was a long-term thing though, and I don't mean to make a big deal of it. Most of their turbos were still working fine after 100K miles, and the pitting was mild and didn't seem to affect performance.

Adrian~

So where does the "pre-turbo" inject? The turbo inlet pipe off of the IC? The air intake pipe? Into the IC? Most water injection systems I've seen are spraying into or above the IC.

I have been looking at the Spearco directions but it is so hard to tell where it's supposed to go, they have install placements for 5 different turbo set-ups and I'm having difficulty figuring it out which applies. Here's a link to the illustation:
www.iconwerx.com/wrx/wi_fig_1.jpg

Yea, using that diagram you'll have to figure out where your carburetor is too! :)

Pre-turbo systems generally squirt right into the compressor inlet.

I'd think the pressure would have to be more to atomize water depending on how large of a nozzle is used and how much boost is run. If you're running 20psi of boost and 40psi of water pressure behind the solenoid it's like having 20psi of pressure(not to point out the obvious). A good test(imo) would be to run 20psi and turn the solenoid on at the lowest duty cycle you will use and see how well the nozzle sprays. I ended up spending about $400 + the cost of a boost controller since I'm using the utecs boost map to control the idc of the solenoid. Would have cost at least $150 less without the aquamist hsv........blah. If I had to do it all over, I'd probably get the aquamist 2c kit. It's more then worth it imo since everything they make seems to be of the highest quality and small at the same time.

peace
I have fitted 2 nozzels in series and my 60 PSI Surflow still mists the water without any problem. So 20 PSI air pressure is not going to overcome the pump.

Yeh, I read what wrx plus said incorrectly. As far as I hear, 40psi is plently. The people at boostcooler make nozzles which flow more water then the aquamist nozzles, and are said to work fine at 40psi(according to the people at boostcooler). I thought it said that the pump was at 40 and the boost was at 20......eh.

peace

Yeh, I read what wrx plus said incorrectly. As far as I hear, 40psi is plently. The people at boostcooler make nozzles which flow more water then the aquamist nozzles, and are said to work fine at 40psi(according to the people at boostcooler). I thought it said that the pump was at 40 and the boost was at 20......eh.

peace

I could be wrong with this, the droplet size of the water mist is largely dependent on the pressure, the smaller the droplet, the larger the overall surface area so cooling effcect is greater.

Larger droplet also causes uneven water distribution amongst cylinders especially the log-shape manifolds. In order to allow cylinder No.1 to receive enough water, you need to over-water the other three - bad for power.

Yes, that is the point I was trying unsuccesfully to make clear, pump pressure has a direct effect on droplet size, did anyone stop to think why the aquamist kits come pre-set at 100psi?

Saabtuner-Saab 99's with pre -turbo injection, that pitted the blades was due to tap water in the tank, against the suggestion from saab to use filtered or bottled water. I went to saab dealers to get that info. I wasn't aware that saab's used pre-turbo w/i, see I learned something today.

Shurflo pumps, I use them in my car but not for w/i. The shurflo pumps that flow 150psi do so at .88gpm and use 11.7 amps, I didn't consider them viable with the plans for my car. Also the size of the shurflo pump dictated a remote location.

Kent

I use a shurflow pump with my setup(along with many other people), and it works pretty well for me. The pump pressure I picked was 100psi(coulda gotten 150), and the amp rating from what I remember is less then 7 not 11.3(since the standard sureflow pumps range from 3-7 amp draw depending on which one you pick). I ended up puting it in the drivers side wheel well with my water container(to keep the water cool). At the same time, it only turns on for short periods of time every few seconds while the system is running to keep the water pressure up. Like I said b4, the people at boostcooler told me that you nly need 40psi(I would guess above manifold pressure) to use their jets. Here's what aquamist says about water pressure...

Specially designed and manufactured by ERL for the sole purpose of pumping water, its delivery rate is small but it generates a very high pressure; a minimum differential pressure of 3 bar is necessary for the ERL atomising jet. There are no mechanical links between the piston and the drive motor: the movement of the special magnetic stainless piston is induced by a powerful maganetic field generated by the on-board electronic controller. Flow and pressure characteristics are controlled by varying the frequency and the duration of the electrical pulse fed to the solenoid.

They seem to think that ya need 45psi above manifold pressure to use their jets. So if the pump keeps 70psi all the time, it's within the limits of what aquamist and boost cooler say works. This is kinda the downfall of my system since I only use the pump to control the pressure of water, but it keeps the pressure above 70psi all the time and I haven't had any problems with it.

peace

I use a shurflow pump with my setup(along with many other people), and it works pretty well for me. The pump pressure I picked was 100psi(coulda gotten 150), and the amp rating from what I remember is less then 7 not 11.3(since the standard sureflow pumps range from 3-7 amp draw depending on which one you pick). I ended up puting it in the drivers side wheel well with my water container(to keep the water cool). At the same time, it only turns on for short periods of time every few seconds while the system is running to keep the water pressure up. Like I said b4, the people at boostcooler told me that you nly need 40psi(I would guess above manifold pressure) to use their jets. Here's what aquamist says about water pressure...

They seem to think that ya need 45psi above manifold pressure to use their jets. So if the pump keeps 70psi all the time, it's within the limits of what aquamist and boost cooler say works. This is kinda the downfall of my system since I only use the pump to control the pressure of water, but it keeps the pressure above 70psi all the time and I haven't had any problems with it.

peace

I may not have made it clear, the pressure of 45psi only applies to aquamist nozzles - other nozzles such as the oil heated type may not need such high pressure to atomise the water - not sure either way, they might even require higher pressures.

I could be wrong with this, the droplet size of the water mist is largely dependent on the pressure, the smaller the droplet, the larger the overall surface area so cooling effcect is greater.

Larger droplet also causes uneven water distribution amongst cylinders especially the log-shape manifolds. In order to allow cylinder No.1 to receive enough water, you need to over-water the other three - bad for power.

I kinda thought about this and have a few questions. Wouldn't the cylinder which gets more water from better flow also be getting more air then the other cylinders? Wouldn't it be good for performance to get more water in the cylinders which are getting more air? With indevidual fuel injectors we assume that all the cylinders are getting the same amount of air, which in reality isn't true. Also, I figure that larger droplets might raise the ability of the droplets to stay cooler longer. Bigger droplets might not have as drastic of an effect on the intake charge immediately, but might have a better cooling effect on the cylinders. Obviously these are all just my assumptions, and I could be totally wrong..... eh,

peace

Hippy-Droplet size is discussed in depth on the waterinjection web site hosted by aquamist. They go into things that are way over my head. But from what I can tell smaller droplet size is desired. Also, I picked-up those amp draw figures for the 150 psi Shurflo pump directly from Shurflo's web site.
www.shurflo.com

Kent

Yeh.... I guess the pump I got uses 8.7 amps at 100psi according to shurflo. Not that it's the best pump to use, but this is the one... (http://www.shurflo.com/pages/new_industrial/Industrial/gen_industrial/genind_doc_sum/8000-543-138.html). The one you were lookin at uses more amps at 80psi(9.1) then the one above at 100(not that it makes a huge difference). eh,

peace

I kinda thought about this and have a few questions. Wouldn't the cylinder which gets more water from better flow also be getting more air then the other cylinders? Wouldn't it be good for performance to get more water in the cylinders which are getting more air? With indevidual fuel injectors we assume that all the cylinders are getting the same amount of air, which in reality isn't true. Also, I figure that larger droplets might raise the ability of the droplets to stay cooler longer. Bigger droplets might not have as drastic of an effect on the intake charge immediately, but might have a better cooling effect on the cylinders. Obviously these are all just my assumptions, and I could be totally wrong..... eh,

peace

This may not be totally true but you are right about the cyclinder that gets more air will get more ater provided the water droplet size is small so that the inertia effect is less pronounced.

Larger droplets cannot change the direction of flow as easily as small one. The mass of air is much smaller than water droplet, approximately 1000 times lighter. 1 ltre of water weighs 1 kg and litre of air weighs 1g.

All this knowledge and research......

Specially designed and manufactured by ERL for the sole purpose of pumping water, its delivery rate is small but it generates a very high pressure
The ERL electro-magnetic pump is the result of a two-year intense mechanical and electronic research and developement programme.
http://www.aquamist.co.uk/cp/sys1/jetrate.GIF

Water pump tech1 (http://www.aquamist.co.uk/cp/sys1/techsys1/pump.html)
Water pump tech 2 (http://www.aquamist.co.uk/cp/sys2/techsys2/pump/pump.html)
Note that there seem to be two aquamist pumps(according to the tech files). One which uses 8amps and flows 160cc a minute, and one which uses 12amps and flows 300cc a minute. I'll use the higher flowing one which eats less amps per cc for this gripe:).

The aquamist pump flows 300cc at 6bar(around 88psi)according to their website. They say that it can pressurize the system upto 250psi with their pump, but that would be at a lower flow. What if ya want more then 300cc's of water? Would ya have to use two pumps if ya wanna keep the pressure at 88psi? If we run a 12.5 to 1 a/f ratio and want 20% water/fuel((to get a 10.4 to 1 liquid to fuel ratio), the pressure would drop below 88psi b4 maxing out stock wrx fuel injectors. If we want a 12.5 to 1 a/f ratio and 15% water to fuel ratio(10.87 to 1 liquid to fuel), the pressure would drop below 88psi with 500cc's comin out of a fuel injector(not even maxin out sti's). Someone was questioning how the shureflow eats up 11.7 amps at 150psi(even though it uses 8.7 at 100psi). The aquamist pump uses 12 amps and at open flow an aquamist system would need to use smaller then a .5mm jet to keep that kinda pressure up. It would need a .7mm(or smaller) jet to keep 88psi at open flow. On the other hand, a shureflow can keep those kinds of pressures in the system while using 4 1mm aquamist jets(or more).

With a given aquamist system, their biggest jet would be the one atomizing at the lowest pressure(at open flow). My point is that it seems like aquamist thinks everyone's using race gas and doesn't need such a rich air to liquid ratio, should buy two pumps, or the pressure in the system doesn't really need to be at 88psi(at least with their jets). Also, does anyone out there know why it took aquamist 2 years to make a pump which doesn't flow as much as their jets? eh,

peace

Hippy,

It would be a good idea to post that question to the vendor section of the forum.

I think if it is possible to combine aquamist's control and shurflo pump together, one will produce a great system that will run up to any water/fuel ratio.

According to this, the 03 aquamist pump can sustain 7 bar at 300cc/min. http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=234. Still cannot match the Shurflo.

Also notice that the you can double aquamist pump for a few dollars: http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=127

I can't remember where I read this from their forum, you only need 3% w/f ratio to replace a/f ratio of 10:1 to 12.5:1 !!! I will look again and try to find it later.

I have found the chart that may confirm my suggestion:
http://www.aquamist.co.uk/phpBB2/viewtopic.php?p=2445&highlight=#2445

Hippy,.....I can't remember where I read this from their forum, you only need 3% w/f ratio to replace a/f ratio of 10:1 to 12.5:1 !!! I will look again and try to find it later....

I have heard the same. This is cause they're figuring that water would have a much greater in cylinder cooling effect. From what I've seen though, just cause the latent heat of water is much higher then fuel that doesn't mean it will cool the cylinders that much more(even though it could). The cooling agent(water or fuel) is only in the cylinder for a certain amount of time, and maybe this short amount of time isn't enough to see the full effect of how water is that mich better then fuel at cooling. I would think it especially true since the water gets heated up a bit b4 it even reaches the cylinders. I mean it might not be necessary to have the same air/liquid ratio as b4 water injection, but I feel safer having a nice rich air to liquid ratio.

At the same time, I would think using more water would just help get more out of the water injection system allowing more timing/boost and what not(could be wrong). This is all me talkin out of my ass and what not, but the point is there are people out there who wanna run a lot more then a 3% w/f ratio. B4 I put my system together I read posts of people talkin about running at 11.5 to 1 a/f with a 15-20% water to fuel ratio on top of that(that's 9.6-10 to 1 liquid to fuel ratio). This is obviously extream, but there are many people out there(like me) who just want to replace the fuel they were using to cool the engine with water. Most of these people will want more flow then the aquamist pump supplies. It might not be necesarry to have a 15% water to fuel ratio at 12.5 to 1, but it just boggles me how the aquamist pump is so limited when it comes to flow(at least by looking at the stats). eh,

peace

I have heard the same. This is cause they're figuring that water would have a much greater in cylinder cooling effect. From what I've seen though, just cause the latent heat of water is much higher then fuel that doesn't mean it will cool the cylinders that much more(even though it could). The cooling agent(water or fuel) is only in the cylinder for a certain amount of time, and maybe this short amount of time isn't enough to see the full effect of how water is that mich better then fuel at cooling. I would think it especially true since the water gets heated up a bit b4 it even reaches the cylinders. I mean it might not be necessary to have the same air/liquid ratio as b4 water injection, but I feel safer having a nice rich air to liquid ratio.

At the same time, I would think using more water would just help get more out of the water injection system allowing more timing/boost and what not(could be wrong). This is all me talkin out of my ass and what not, but the point is there are people out there who wanna run a lot more then a 3% w/f ratio. B4 I put my system together I read posts of people talkin about running at 11.5 to 1 a/f with a 15-20% water to fuel ratio on top of that(that's 9.6-10 to 1 liquid to fuel ratio). This is obviously extream, but there are many people out there(like me) who just want to replace the fuel they were using to cool the engine with water. Most of these people will want more flow then the aquamist pump supplies. It might not be necesarry to have a 15% water to fuel ratio at 12.5 to 1, but it just boggles me how the aquamist pump is so limited when it comes to flow(at least by looking at the stats). eh,

peace

The aquamist pump started its life with WRC rally cars requirement - I know for a fact that the Prodrive's Subaru uses a 0.5mm jet and one aquamist pump. These cars run awesome boost, about 4 bar absolute!

I suppose it doesn't really matter how much water you decide to run as long as it doesn't cause power loss or blowing out the sparks. The 3% mentioned is just a comparison between the latent heat capacity of both liquids.

I agree that there will be some cooling capacity loss of water up to the position where the fuel injectors are located. After that point, they should both experience the same heating treatment until they exit the combustion chamber.

As regarding the capacity of the aquamist pump, they may think that if 3% is plentyful, which equates to approximately 60cc/min (based on 2 litre/min of fuel). 300cc/min (x5) is plentiful. 150cc/min of water absorbs nearly 9 BHP so 300cc/minute takes some 18 BHP away from the engine.

As said before and plus the links above, there are several ways one can increase the flow capacity of the aquamist pump but most people choose to ignore it - I think cost is a major factor when flow/buck is considered and Shroflo comes up top every time. On reading their Forum again, Aquamist do have systems that use Shurflo pumps.

Yeh, if ya start out with a wrc car you're gonna use less water cause you're not running on 93 octane and don't need as much cooling as if you did. A lot of people are looking towards water injection because they can't even get 93 octane where they live. I just finished tuning my car on 100 octane(first time with water injection) which uses a lot less water then my 93 octane map(more like 6% water/fuel where my 93 octane tune uses 15ish percent). Eh, just gripin about a pump that I will never have I guess.... It was just strange to me cause the whole system is so nice other then the flow of their pump(sorry to repeat myself). I have a few question though. Are you saying that adding water kills the power of an engine? Is this without tuning or something, or is it because of how it slows combustion? Is it at a specific rpm, or is it through the whole rpm range? I can tell ya that the difference with my car running my old 93 octane map verse the one with 15% water/fuel is like night and day(I didn't lose 18hp). eh,

peace

I am expecting the answer to your question or 18BHP loss is only theorical - 300cc/min of water, when fully evaporated will take away 18 BHP or 12 KW for sure.

There are other factors that will turn this loss in to gains:

1. Inlet temperature drop increase air density: gain minus very slight displacement of volume
2. Cooler condition in the combustion chamber during the induction stroke increase the volumetric efficiency: GAIN
3. Allow running 12:5 1 a/f ratio: - GAIN due to less CO production to suppress complete combustion.
4. Ignition advance is possible since water will keep excessive heat buildup on the piston crown -stop the pistons from loosing strength and hot spot that may cause detonation: GAIN
5. "Effective Compression" gain due to 1,400 times volume increase when water turns into superheated steam. Torque increase or average cylinder pressure increase without excessive heat (EGT): GAIN

These above GAINS should more than ofsetting the 18BHP loss. But you have to run the correct amount of water to balance the loss/gain.

I have learn much from the "www.waterinjection.info" site (former Turboice information site) - all the above theory is proven and published by a collection of scientific Journals and SAE papers.

I am in agreement with you entirely - the gain is imminent.

Here's a little quote from the question answer/faq section on the aquamist website.

6. How much water do I need?
From the mild to the very wild, the quantity of water injected is normally between 10% to 25% related to fuel flow.

Here's a little quote from the question answer/faq section on the aquamist website.

How much water are you using in flowrate terms - is 20% of 2 Litre fuel is 400cc/min on a 93 octane fuel about right to keep your engine from knock and good ignition timing?

Like I said b4, lately on 93 octane I have been using a 15% water to fuel ratio with a a/f ratio of 12.5 to 1 making the a/l ratio about 10.8-11 to 1. 20% would leave me with a 10.4ish to 1 air/liquid ratio which even though it wouldn't be terrible(since many wrx's actually run that rich of an a/f ratio), I have decided to use a little less water:). Course I haven't used water injection for a long time and I'm still experimenting. Maybe next week I'll have a 93 octane tune with anywhere from 10-25% water to fuel? It's nice to know that my pump would be able to keep up with that kind of flow even though I might never use it. Was that the question? eh,

peace

Perfect! those are the answers I was looking for. Please keep us up to date, I am very interested in real world data when thre are so many tuners still believe that the concept is a "band-aid" and doesn't belong to proper tuning.

I hope you are able to prove all those people wrong. Thanks for the input and the chat.

I've never really heard the bandaid thing b4 about water injection, even though I've had people say that about other things I've chosen to do with my car. Water injection's like having a bigger radiator, intercooler, and fuel injectors all in one. It's also the only mod I've done which helps me save money in the long run. Using around 14% less fuel at hard throttle is nothing to laugh at, especially since that's usually when wrx's F reading on the dash goes to E. I read up on water injection b4 I decided to try and make my own system. The people who had tried it and the documentation on it all lead me to beleive that it would be a really good thing for making more/safer power, and I totally agree. I'm a big fan of water injection after seein what it's done on my car so far and imo it's more of a cure for cancer(rich fuel ratio/detonation/preignition/overheating/low octane/high gas prices) then a bandaid.

peace

I have one more question, quite an important one.

Most tuner regards water injection is not an good idea because when the water runs out, the engine goes bang.

Do you have some provision to lower boost when you are out of water?

In my case, because I use a stiff wastegate spring, there would be no way to lower boost electronically to something that would be so low that the lean mix and advanced timing wouldn't be dangerous. When I'm out of water, I bump the UTEC remote switch up one spot which is a "dry" summer map and continue on happily. The shurflo pumps are safe to operate dry, by the way.

I use the utec too. Since I started using water injection, I've set the utec so that when it detects a knock it retards more timing then when it did back when I wasn't using water injection(since the timing is more advanced while using water injection). I also have the "basemap" in my car which was as mac said, a "dry" map. I haven't had the water run out or a clog in my system yet, but if I did I would just switch from the water injection map to that one. Once I tried to run the car hard without turning my water injection pump on though:)....<flashing cel>......<flip switch on(for water pump)>. Since then I've made the pump so it turns on with the ignition and with 4psi of boost pressure(while retaining the switch so I can turn it off if needed, but it's always been in the on position so far). I use the water injection map/tune 99% of the time.

The other 1% of the time I use a water injection/n2o/93 octane map. I use a single fogger wet n2o system with it, and it's pretty nice.... I've kinda been waiting to tune for higher octane because I wanna change the n2o system a little. It works fine, but I wanna have it so the water injection system is hooked upto the fuel port on the n2o/fuel fogger so that it puts a static amount of water out while being used instead of fuel. It would just make me feel safer if there wasn't fuel going through the intake system of my car, and it might be easier to tune the fueling. Maybe I'll just get a dry fogger? eh, I dunno.... Just some random stuff I guess.

peace

It appeared that running out of water is not a really an issue, both cars have fall-back maps to allow timing adjustment.

I wonder why so many tuners are so reluctant to use water injection, instead they advise strongly against it. I have seen many posts on other threads that dyno charts were posted to show drastic power loss. My suspecision is that you cannot run over-rich map as well as injecting water.

What would one do if the car is factory standard and user cannot trim fuel and ignition map, WI is not useful in those occasions?

From what I've seen, the power loss was from bad tunes on simplistic water injection systems. If a tuner isn't used to pulling the fuel to 12.5 to 1 on a wrx with 93 octane, it can be hard to do. This and advancing the timing so much was really scary for me when I started tuning my water injection setup. Anywhoo, a lot of tuners don't remove enough fuel and at the same time have to much water in most of the rpm range because the water injection systems they use only have an on/off type of flow instead of an adjustable rate where there's more water while the rpms go up.

With and on/off solenoid and one size jet, tuning water injection is much harder then tuning alcohol injection. This is cause alcohol is fuel, and water isn't:). A setup could run a really big alcohol injection jet and have the mixture of alc to 93 octane be 95% to 5% at 4000rpm. As the rpms rise, the alc jet would put out the same amount of alcohol, but the fuel system would put out more 93 octane(to keep the same a/f ratio) changing the alc to 93 octane ratio and resulting in the octane going down the higher the rpms go. This is just an example, because there are obviously many ways to tune any setup. Since water injection isn't fuel, we can't use a huge jet or the car will bog at low rpms from to rich of an air/liquid ratio. With on/off type systems, the jet needs to be small enough so that at low rpms there isn't a higher water/fuel ratio then we want, and this limits the water injections ability up top(cause it flows a small amount by using that jet, like a constant 100cc, or 50cc's). If the system has a jet that's a little better flowing, there would be more water then we want at low rpms, the right amount of water in the middle rpms, and not so much water in high rpms. This limits the effectiveness of the water injection system.

When coupling the simplistic system with people who aren't ready to pull enough fuel, you could end up killing the overal performance of any car. Imagine someone using a 400cc a minute nozzle with a on/off type system and complaining that the car lost power at an 11.5 to 1 a/f ratio. Could make the air/liquid ratio rediculously rich, especially at lower rpms....... In my opinion, those systems even though not perfect can be tuned much better. Having a leaner then normal a/f ratio at lower rpms and a little richer uptop(like moving from 13 to 1 to 12 to 1 as the rpms rise) with the right size jet might be the way to go with that type of setup? I don't know. I do know that if ya pump a bunch of water into the engine without removing the same amount of fuel and or advancing the timing a bit/upping the boost, you will lose power.

It's not like a radiator that you can pop onto the car and expect that it will do its job well. It's part of the fueling system(kinda). What would you think would happen if ya popped 400cc's of fuel into the intake throught the rpm range at hard throttle on a stock wrx? This wouldn't be as drastic(powerwise, I dunno about engine safetywise) as puting 400cc's of water in either, because water slows the combustion process more then fuel(water doesn't burn). The key to water injection is the tuning, and if a car loses power with water injection, imo that's a reflection of the tuner and their ability to tune the setup correctly. As always, this is all just my opinion from what I've read and seen, and I'm no expert.

peace

It appears that you have unlimited patient and if you don't mind, I like to know more.

You explained very clearly on a fix rate inejction system and basically you need to tune around it rather the WI tune to the engine's requirement, not really a problem. All one needs to do is use it on a limited range such as the peak torque region and let the water to air ratio decay slowly towards the higher RPM range natually.

I wonder if your system is able to vary the water flow or you need to do quite a bit of work on the utec. It appear that you have somehow managed to use WI injection better than a few well-knownl professional tuners, just wish they will come out of their little room and learn a few new tricks.

I just have a lot of time, and not much better to do:). My system isn't great, but I can adjust the flow dependent on rpm/tps. I wish it was based on rpm/boost, but I'm using the utec's normal boost map to control a solenoid which changes the flow of water dependent on what's in the map. There might be a utec update eventually which changes the boost map into a water injection map by having it be boost pressure instead of tps, but that's not around at the moment. There used to be a version of utec that did this(special water injection edition), but it was on 3.1 software and I'd rather use the new utec software with open loop fueling. Anywhoo, my system basically kicks on at a given psi, above 40% throttle position, and above 3750 rpm, then dishes out more and more water as the rpms go up under hard throttle. I basically started with my normal tune, and started advancing the timing/leaning out the fuel at 4000rpm, and continuing all the way to redline. If the adjustability was rpm vs load(boost pressure), it would be easier for me to tune it better(more controlled flow over a wider range of situations), but the system works well enough for me.

peace

It's really not very complicated even with a static flow system. As the water/air ratio drops, richen up the fuel mixture to compensate. On my summer map I run AFR around mid 11's in the mid range (3-5k RPM) gradually trailing down to mid 10's at redline. The limited flow of the turbocharger is convenient in this case. Not ideal, but works well.

Hippy: what solenoid do you use?

aquamist hsv..... It's nice, but it basically cost the same amount as all the other parts in my water injection system put together(maybe even a little more then all the other parts) which sucked. Changing a $200 water injection system into a $400 water injection system with one part. eh,

peace

aquamist hsv..... It's nice, but it basically cost the same amount as all the other parts in my water injection system put together(maybe even a little more then all the other parts) which sucked. Changing a $200 water injection system into a $400 water injection system with one part. eh,

peace

Why aquamist valve, there must be other solenoid valves that with work with pulsing and cheaper?

Ahh.. didn't realize it was so expensive. I'm thinking of using the factory boost control solenoid attached to the boost-referenced pressure regulator I have in my system to allow me to bleed off air in the mid range and control flow that way (effectively creating a water pressure map). Lots of testing would be required, though.

yeh, I dunno.... I didn't look around that much b4 I got the solenoid. It's the smallest solenoid I've ever seen, about the size of my pinky....... I'd bet there are much less expensive ones which do about the same thing, just didn't feel like lookin all over the place for something that might work when there's something that I know would work well. Ever wonder why aquamist systems cost so much? Well, when they chargee 200 for the solenoid...... Aquamist makes some nice stuff though, even though it's expensive. I ended up using that, some aquamist jets(a .4 and a .7), and some 4mm tube......

peace

I know for sure that exchange rate has a great deal to do with it, a year ago the system1s is around 400 dollars and now nearly 600 dollars. May have to wait for the dollar rate to go up after the election.

I got my 2d system about a year ago for $690 from a vendor here in the US. I thought briefly about fabricating my own system, but decided that proven reliability was worth the cash.

Kent

Some interesting news on the thread below, Ecutek will not be working with Aquamist (so it appears) on an integrated system.

http://forums.nasioc.com/forums/showthread.php?t=443134&page=2

I feel quite sad to hear this but may be their is some hope that aquamist may go alone due to this announcment from Ecutek.