I have researched water injection and come to the conclusion that it is a viable option for reducing intake temps and suppressing det. I would like to know everybody else's opinions. I am talking about high quality/high pressure/highly atomized W.I., not the windshield sprayer nozzle in the intake pipe setup. The biggest problem with the stock turbo on the WRX is its inefficiency(read:temps skyrocket) once it goes over 18-19psi. Am I wrong in thinking that water injection would allow much higher boost levels in stock trim, without worrying(as much) about detonation?

Any and all opinions welcome/encouraged,
Tim

Tim,

This is NOT the way to use WI. You'd be fighting a losing battle.

You'd be far better off changing the stock turbo first. At the boost levels you're talking about, your intake temps are probably reaching 60C +++ (I'v seen 75C on some cars) on a hard run.

At this level, you'd have to throw so much water at it, that you'd probably lose, more than you'd gain.

However, if you were to use WI, keep the boost sensible on the stock turbo, and remap the fuel, and ignition, then you'd see gains, and it would be safer.

Start off with a well matched turbo, and mappable ecu. If you can, a FMIC. Once you get the charge density under control, and a GOOD tuner to map the ecu, WI will really come into it's own.

At this point, the WI will allow you to advance the ignition by several degrees, and up the boost, if the engine is up to it.

IMO, WI is an excellent addition to engine tuning, but it can only do so much. Ditching the TD04 would make a better starting point.

Happy.

Don't worry, I wasn't going to just slap on the WI and crank the boost. I agree that the best setup is an overall well designed system. Well, I don't plan on swapping out the turbo, atleast not anytime in the next two/three years. If anything I will have it ported. I know the TD04 can be made to support atleast 350hp, with the right porting of course. What I would like is to have the WI and remap the ECU so that it doesn't dump fuel to prevent det. Water has a little over 4X the latent heat capacity of air, and while I don't know what it is compared to fuel, I know water is much better. I live in Texas and the summers(most of the year) are ridiculously hot and heat soak is inevitable. First I was considering a water spray system like on the STi's but compared to a properly designed WI, it doesn't do much. I don't see FMIC's as practical, atleast not with my setup/preferences.
oh god, I just saw the time, I have to go to bed. thanks though happy, for your input, please keep posting to this thread once other have responded.
Yawning,
Tim

I think water injection kits can be very effective, they lower the temps in the combustion chamber (fighting detonation, as you said), and also have the nice cleaning effect of removing carbon buildup! You don't see it used much here in the states, but don't some cars in Europe come from the factory with this as an option? (Cosworth comes to mind)

Kevin

www.forcefed4.com

Don't get me wrong, I LOVE WI, and have run it for about 2 years. It's certainly more effective than water spray. I was just trying to answer in the context of the post.

Now, 350bhp, out of a TD04, that I'd like to see, poor little thing will have a coronary........ :lol: if you get 300bhp you'd be doing well........

Happy.

There is a place south(i think) of Austin, TX named Forced Performance that does the turbo porting to make it support 350HP. Another I-club member has had it done. Dave Angenend is his name. There is also an aftermarket kit for a Chevy V8 (4.3L I believe) that uses the TD04 to make 400 Hp.

The cleaning effect is another great benefit WI. That carbon buildup is another source of detonation. I've heard of many people opening up their engine after thousands of miles of use while using WI, to find what appeared to look like a brand new engine. Plus, it keeps emissions down, which is good for all of us, especially those without cats.

Happy, what type of WI system do you use?

Cheers,
Tim

Water injection can be very effective, and being just up the road in Oklahoma City I know what you mean about heat soak on hot days during the summer. A lot of Saab guys running high boost use w.i. with very impressive results. Post your results when you've got this installed, although it will now probably be next summer before we know just how useful it is.

how does water injection work?????

I have water injection in my WRX. Basically, it is a home made system, but I used a high pressure diaphram pump so the water is well itomized when spray. The water jet and the switch is from aquamist. I still using stock boost level, but the car seem to performed better.

How much were the switch and jet from aquamist? I probably won't be installing WI in the near future, as the temp just dropped to 40 F(cold for TX) this afternoon. Most likely, I'll put some system on in the spring. I still want to hear other people's experiences. Anyone use WI and not like it? I like to get all the angles before doing too much.

Tim

Also, where did you get the diaphram pump and what did it cost?

Here is a good write up on the aquamist system;

http://www.twinturbo.net/cgi-bin/ttnet_viewmsg.pl?forum=main&msg_id=696410&words=aquamist


joe

The pump is from Surflow and weight 5 pounds. It can run dry without damage, rebuildable and can put out more than 70PSI. It has its own adjustable pressure switch Cost is about $65. The switch and jet nozzel is from F-max and cost $50$. I mounted the pump under car near the right rear wheel. A 2 gallon gas tank sit in side the trunk with a bracket. It takes some fabrication to mount the pumb and tank, but it is cheaper then the aquamist base system, and I think it works just as well. I like it.

Found this pic' of my WI/IC WS setup. It was taken before the 2.5lt conversion. Sorry for the pic' quality. The car is an STi4 Jap inport.

I use a modified ERL Aquamist system 2S for WI, and a modified 1S for the IC water spray. The WI uses a high speed valve, controlled by the MF2 controller. The "tubes" are air damped to smooth out the pulses from the pump, and also compensate for any water pressure anomolies.

It's all mounted to a stainless steel plate, which replaces the bracket that retains the battery. The battery has been replaced with a lower one, so I could shut the hood :rolleyes:

The Aquamist pumps have a working pressure of 140psi (adjustable on the 2S).

I have a custom trunk mounted water tank, with low level sender (led on dash) and individual feeds for WI/WS. I also use a small pump in the trunk to feed the WI, because on hard acceleration, the system was getting knocked out.

Happy.

I reckon if it's good enough for Prodrive, and most of the other WRC teams, it's good enough for me.

Originally posted by Happy
Found this pic' of my WI/IC WS setup. It was taken before the 2.5lt conversion. Sorry for the pic' quality. The car is an STi4 Jap inport.

I use a modified ERL Aquamist system 2S for WI, and a modified 1S for the IC water spray. The WI uses a high speed valve, controlled by the MF2 controller. The "tubes" are air damped to smooth out the pulses from the pump, and also compensate for any water pressure anomolies.

It's all mounted to a stainless steel plate, which replaces the bracket that retains the battery. The battery has been replaced with a lower one, so I could shut the hood :rolleyes:

The Aquamist pumps have a working pressure of 140psi (adjustable on the 2S).

I have a custom trunk mounted water tank, with low level sender (led on dash) and individual feeds for WI/WS. I also use a small pump in the trunk to feed the WI, because on hard acceleration, the system was getting knocked out.

Happy.

I reckon if it's good enough for Prodrive, and most of the other WRC teams, it's good enough for me.

Wow! Nice system Happy!

That must have cost a bundle! I dont think Ive got that much money into my Dodge including the car!

You will rebuild your engine quite often I've pulled engines apart that have run WI, and it's not a pretty sight at all. As stated above, you are better off matching the turbo to what kind of results you need.

You can use WI, it's your car, but most hard core racers run this and rebuild the engine after a race or two. But it's your car, do what you will....

Originally posted by syntrix
You will rebuild your engine quite often I've pulled engines apart that have run WI, and it's not a pretty sight at all. As stated above, you are better off matching the turbo to what kind of results you need.



Please explain what you found.

Syntrix,

Well I can only comment on my, and friends results. I've been running it for about 2 years, as already stated. I recently stripped my STi engine, due to a head gasket failure, and the internals were just fine.

I made the comments about correct sizing of the turbo, and intercooler, but even when you've done that, there are still benifits from WI. Or sometimes one has to compromise, due to lack of space, money, etc'.

It would be good if you could qualify your comments, like what system, pressure run, what was run (methanol, etc') % of mix to fuel, etc', etc'. Did anyone bother to check the acidity of the local water.

Then I'd like your comments on the effects on the engine internals, when driving in the rain, fog, snow, and for those people who live in countries/areas with a very high RH.

Happy.

I live in a humid swamp. The average ambient humidity here is around 90%. Most of the time it's 100%.

Yes, we still have plenty of cars around here. None of their internals have rusted or rotted from the ambient humidity. What in the world are you talking about, syntrix?

In the GN world, they run water injection for years. They don't have to rebuild the engines after every two or three 1/4mi runs. :confused: :confused: :confused:

I must agree with everyone else here, WI does nothing to the internals except clean them of carbon. If anything, it allows the oil to lubricate better because the cylinders are not being washed down with gasoline, which dilutes oil(assuming your ECU is tuned not to run rich for saftey). A friend has a 700 hp Buick T-Type with 150,000 miles on it, 50,000 of them with WI. He recently tore it down and it looked better inside than it did before he put the WI in. The REAL race teams that run WI rebuild their engine after every race because they are running on the limit for long periods of time. Any engine that makes 350 hp through a 32mm restricor is going to be built for power, not reliability. They have to run ridiculous amounts of boost to do that.

If you are indeed serious about these engines being damaged by WI, do you think you could show me pictures or tell me in more detail what it does to the internals? I would like to watch out for the health of my car. I need to know more than just that I will have to rebuild my engine.

Tim

No, I don't have pictures, but I've pulled apart many forced induction engines where people ran WI. Heads are not very nice looking and tolerances wear very quickly for some reason.... all based on similar setups without WI.

Just remember that the water is replacing air and fuel, the two basics on your car. When the water vaporizes, it expands..... cleans... damages.... enhances? All I know is that any WI car engine that I've torn apart has been in bad shape. You can all debate why, I don't care... it's your car; not mine :monkey:

Syntrix,

I suspect that you have no idea how much water goes through an engine, via the intake, on a simple rainy day. FAR more than a correctly set up WI system. Same goes for cars living in a high RH area.

If you think there's a problem with the expansion of vaporising water in an engine, you must be positively mortified thinking about the expansion of all that air, and fuel going bang in the cylinders :eek: :lol:

The only associated problems relating to WI, that I'm aware of, are not running a methanol mix in winter, and the WI system freezing up, and like I already asked you, water being used with a VERY high acidity, which more commonly also damages the pump, not the engine.

"enhances ?", I take it that you've not tuned an engine, with, and without WI then :lol:

Issues should be debated, that's how we learn,

Happy.

The only associated problems relating to WI, that I'm aware of, are not running a methanol mix in winter, and the WI system freezing up, and like I already asked you, water being used with a VERY high acidity, which more commonly also damages the pump, not the engine.


Happy I know that some Group A cars like the Celica TTE (the last Grp. A) which is runned in our local Rally championship uses a mixture of METHANOL with WATER for their water injection systems ..... and the lowest temp we have here in winter time is 10 C.
Even some Group N WRX cars use water injection, BTW looking at some FIA homologation information I found out that FHI (Fuji Heavy Industries) homologated water injection for the Grp. N WRX since 1996.

Carlos H.

Carlos,

Methanol isn't just used to prevent freezing. It also has a better latent heat capacity than water, and will also give extra power. One of my friends is currently running 100% methanol through his WI.

Thanks for the info,

Happy.

uhmmmm 100% methanol ..... well that should also help to raise the octane level of the SUL fuel.

Carlos H.

Originally posted by Happy
Syntrix,

I suspect that you have no idea how much water goes through an engine, via the intake, on a simple rainy day. FAR more than a correctly set up WI system. Same goes for cars living in a high RH area.

If you think there's a problem with the expansion of vaporising water in an engine, you must be positively mortified thinking about the expansion of all that air, and fuel going bang in the cylinders :eek: :lol:

The only associated problems relating to WI, that I'm aware of, are not running a methanol mix in winter, and the WI system freezing up, and like I already asked you, water being used with a VERY high acidity, which more commonly also damages the pump, not the engine.

"enhances ?", I take it that you've not tuned an engine, with, and without WI then :lol:

Issues should be debated, that's how we learn,

Happy.

All aquamist systems. You can't be serious about the giving water concentration over a given volume between a foggy day and a squirt with the WI system? There is so much more water when the WI is active than any humid or foggy day ;) LOL


That's great that you are running a WI system, and have tuned it. .... those are questions, hece the ? above.

When was the last time you took your engine apart, and how long have you been running the WI system?

Sure you can push things more, but you are displacing air and fuel and replacing with water. It will reduce knock or detonation so you can squeeze out a % or two...


Like I keep saying on here, it's your car, do what you want to! LOL

I don't mean to be picky Happy, but I think methanol has a slightly lower latent heat capacity than water, which is still significantly better than fuel. It burns too, and it still cools very well. You're also right about the pumps usually being the thing to go. You can find pumps that have internals treated for alcohol use. That diaphram pump from Surflow sounds pretty good to me. I am going to see if I can get more info on it. Do you know how much the ERL pumps runs alone?

Tim

Syntrix, please elaborate on the damage it causes to internals. It is my car, and I want to know what could happen to it if I used WI. How many engines have you opened up that used WI? What did the parts look like? Please don't just come back and tell me I'll have to rebuild my engine.

The last time I took apart an engine that was run with water injection was my friend's Buick T-Type I mentioned earlier. It was run for 50,000 miles at 500hp or above. Looked pretty clean to me. No pitting of any sort, no rust, it did have really clean oil though. All I'm saying is a properly tuned WI system has many benefits, one of them being that it doesn't eat away at your engine. I want to know what happens to an engine with a poorly designed WI system.

Tim

Syntrix,

I ran the WI for about 2 years on the EJ20 STi engine, and as I said in a previous post, I had a very good look when the head gasket went. The engine's still in bits, because I got slightly side tracked with the EJ25 project :D

If you "just" fit WI, and don't remap the ecu, you will LOSE a little power, 5~10bhp, with 10% water to fuel injected: BUT, remap the fuel, and advance the ignition, and then you'll not only gain more power, but the engine will run safer too.

Something else to concider. We did some testing on a chassis dyno, and found a 20bhp difference running water "on", to water "off". What was actually happening, was that the extra heat induced by the dyno, was sapping power. The WI wasn't "increasing" power, it was reclaiming "lost" power. This works the same on the track, or in hot weather.

Re water through the intake in the rain, or in high humidity, comapred to WI, "serious" VERY. YOU'D BE AMAZED, I was. I can't remember the equation to work out volume of water vs %RH, but I'll try and dig it out.

DJWRX, I'm fairly certain that methanol is better than water for cooling, but I may be wrong.

Try Jackson Racing for prices, I believe they are one of the main US dealers.

Happy.

Originally posted by Happy

DJWRX, I'm fairly certain that methanol is better than water for cooling, but I may be wrong.


Happy.

Specific Heats:

Water: 4.18 (J/g)/deg C
Ethanol: 2.46 (J/g)/deg C
In order to raise the temperature of one gram of water, one degree celsius, you must supply 4.18 Joules of energy.
In order to raise the temperature of one gram of ethanol, one degree celsius, you must supply 2.46 Joules of energy.

This means that each tiny droplet of methanol can actually hold less energy that each tiny droplet of water, before each turns to vapor.

I knew those chem classes would be useful one day.
Tim