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Does anyone on this forum have experience with water injection? I plan to use it in the future. I would like to know what the people here think of it first, though...
Based on my searching, I believe the systems from www.coolingmist.com to be a very good value. What do you think of these products and the technology in general?
I know it is kind of "new school" but it has many enthusiatic proponents. What say you?

zambon wrote: I believe the systems from www.coolingmist.com to be a very good value. What do you think of these products and the technology in general?
I know it is kind of "new school" but it has many enthusiatic proponents. What say you?

I thought water injection & water/methanol was "old school", its been around a long time and was used with non intercooled turbo/supercharged engines to help against knock by reducing intake temps but they're a little risky an not that reliable

Don't base your supercharged engines margin against detonation using this, what if injector fails + basing engine on a consumable fluid not really the way to go.

Use an intercooler and forget about water injection all together.

Water Methanol injection will cool the air more than an intercooler. It will generally cool the air to somewhere between ambient and the temperature of the injected water. However the density increase due to cooling is somewhat offset by the increase in humidity.

I am not sure it's just old school, don't most WRC cars use water injection?

As Matt pointed out if the system fails and you are using it to protect against detonation that could be a problem. However it's really not that bad. First of all injectors in most systems are just little holes with no moving parts, so they won't fail. The risk is a pump, check valve or solenoid failing. To protect against that I suggest a warning buzzer that goes off during boost if water pressure is not sensed downstream of the check valve.

There is a lot of mis information out there about these systems. However it was proven long ago that they do work if set up correctly and may competitive racers still use them. I suggest reading either stuff written on it by NASA, or Sir Harry Ricardo's incredible book, The high speed internal combustion engine.

I'd only use this system together with a modern engine management.

An engine with a good knock detection could together with water/alcohol injection use slightly more boost and if water is not available the ECU would keep the engine from self destructing.

A system spraying water on the IC goes into the same class of gizmos and can also be useful in some cases.

micke,

Can water injection bring down NOx readings for high compression engines?

Micke wrote:
A system spraying water on the IC goes into the same class of gizmos and can also be useful in some cases.

Air to Air intercooler can be 5 to 10 % more effective this way but.....still a consumable fluid etc

What are you planning Zambon, street,track or Drag runs

Zamani i think its possible to reduce emissons with water injection.....i remeber reading some where about water injection on high comp N/A motor reduces emmisons because water inj' lowers gas/air temps in combustion chamber and this allows for "easier" expansion/burning of the charge after ignition = a more complete burn = less emmisons....but tis a vague recollection at the back of my mind and if it really did make a difference i guess alot more people would be using it.....

Old school for professional racers, perhaps, but I think it is new school for home garage flunkies like me. Doesnt really matter what school...

I am not worried about a clogged nozzle, solenoid failure (the systems in the link dont use a solenoid), or running out of liquid.
The kits sold on the previous link have clogged nozzle detectors. They also use filters in the lines. The problems due to running out of liquid can be addressed with float switches inside the tanks, as well as adequately large tank capacity to accomodate potential needs.

Pump failure is an issue, but from reading the cooling mist site and looking at others, I have noticed that some people use their pumps at higher pressures than the pumps are rated for. I am guessing that this is a risky idea because it could cause short pump life. I dont think that pump failure would such a huge risk. Even so, the clogged nozzle detector would alert the driver if water stopped flowing (I think).

Many of the so called negatives listed here can also be leveled at water to air intercoolers. Pump failure can occur with an intercooler too. Also, if a leak were to drain coolant from the system, the intercooler could be compromised.

I would like to see myself using water injection and a water to air intercooler together. The application, in my case, would be an MP90 supercharged engine running on MegaSquirt.

Some people here believe that the supercharger will cause hot intake air, so I want to do my best to address this potential problem.

Oh, not to try to sell for that site that I linked, but they claim to have a zero percent failure rate on their check valves.

Ive only seen successful setups work on alcohol based drag cars, where the methanol provides enough octane and density to run aggressive ignition. They only need it for 8 secs.

The WRC cars use a setup onto the intercooler from memory, not into the inlet manifold, IIRC. Then again, if they did use it into the engine, it would be to overcome the massively tortured air as result of the 34mm restrictor they have to run over the inlet for the compressor housing.
What works well in motorsport is not always the best for a road car!

Is this just to avoid the setting up of pipework, end tanks, and an intercooler core?

Sure, short cuts work, but for peace of mind, and not having to fill a tank up everytime you go driving, just put a reasonable intercooler onto it.

From what I have seen it’s a band-aid fix or a looking for every hp mod.

I think you will have more problems then anything else.

Like everyone has said good intercooler or similar would be a better long term choice. But say in the 1/4 situation you might use water injection to run that little extra bit. But its never water alone almost always a mix. But then again why not just try a better fuel, etc.

Another option is a mist spray on you intercooler to displace heat, works pretty when you’re on the move.

You can go so many ways, you have to decide the use of the car first then choose how you setup the car around its use.

Why use it? Because it works. It will cool the air far more that an intercooler alone. It doesn't take much searching on the internet to find dyno test after dyno test showing that it allows more boost and more power.

It's been studied extensivly by NASA and it was used heavily on WWII aircraft, in fact most of the succesfull planes from that war used it. It also allows much higher takeoff weights in Civil Aviation on both supercharged piston engine and turbine engine aircraft.

However there are some real downsides and it suprises me that nobody here has really touched on them. The biggest problem when using it with a positive displacement blower or a Turbo is the issue of increasing demand as RPM rises. Most of the kits out there don't address this at all. Some do but they are very expensive.

Here is the problem. In order to bring temps down near ambient the system must inject enough water to bring the air up near 100% humidity. Of course going over that would result in having water form in the intake system so lets shoot for a safer 80% and accept temps close but not quite down to ambient. Now most systems are set to turn on at a certain boost level and spray in a fixed amount of water, lets call that amount X. Now lets say the motor gets enough boost to need the system as low as 2000 RPM (quite realistic with properly sized turbos, or a good Roots setup). If quanity X is enough to bring temps down near ambient at 2000 RPM, it will only be about 1/3 enough at 6000 RPM. So you won't get much cooling at higher RPM where you are looking to make power. If you set it up the other way, where it injects enough water to cool the air at 6000 RPM then water will form in the intake system at lower revs quenching combustion and causing a loss of power or worse.

Some companies try to address this with dual or triple stage systems, but those really on help centrifugal superchargers. These "multi stage" setups trigger additional flow when they see an increase in boost. If your car makes 1 pound of boost at 2000 rpm, 3 pounds at 3000 and 9 pounds at 6000 a triple stage, boost activated system could be for you. Set each stage up for the known boost levels/engine speeds/airflow amounts and the quanity will be close to correct across the board. However Roots blowers makes a pretty flat boost curve, and a Turbo is about perfectly flat once it come on speed.

What we need is a system that measures air flow and temperature calculates and injects the correct amount of water throughout the RPM range. There are systems that do that using a G.M. mass air flow sensor, so perhaps those could be adapted.

I don't think I would be too worried about failure of the system causing engine destruction. You can build safeguards into it. With forced induction everything is more critical, you could also ask, What if my EMS malfunctions and destroys my engine, what if my wastegate fails and overboosts my motor. Even with Good old reliable L-Jet and super conservative settings there are plenty of failure mods that could destroy a forced induction motor. For example a coolant temp sensor failure or AFM failure could do it.

If you want to use water injection then do it! It will help, but unless you are going with some sort of speed/density based system you won't get the tremendous cooling that the makes talk about on thier record breaking cars and would be better off with a good intercooler. Then again, a basic water/meth system would be better then nothing!

Oh, and of course the humidity effects the air density. Remember the whole point of a supercharger is to increase air density in the combustion chamber. An increase in humidity will decrease air density partially offsetting the increase in density from cooling.

In other words, Intercooled air at 150F is more dense then water injection cooled air at 150F. Of course if you were to inject water into that 150F intercooled air it would be even more dense which is why intercooling combined with water injection is so effective.

I hope I am not creating more confusion here.

fuck, i'll read that when i can be fucked its 3am.

from the first 2 lines all im gonna say, ye its good n all but who can be shitted filling up a tank n mixin all the dam time.

on a stock carby car on the dyno we injected water into the carby and got a constant 3kw gain going back and forth. lol it was pretty funny.

Same as a proper meth\water injected intercooled car.

GTV6GPTT, I am not quite sure I understand what "i'll read that when I can be fucked" means. That must be some sort of Australian phrase. Have a good night.

go on mate, give us a go. bit of a nipper un the kepler’s. cheers fella done be a drain on the weasel and the cracka. Whoroo this crocs a big one! SHES GOING INTO A DEATH ROLL

i mean i cant be bothered reading that long post and computing it in the AM, get back to it tomorrow.