effictivness of water injection

[Hit_N_Run-player]

so far from what ive been looking up on water injection, its pretty much like your engine trying to compress concrete in your engine because the h2o is not a compressible element like say n2o and the water would cool off some spots, but it wouldnt just do that and burn up. I dont know, im not really familar with the subject so dont quote me on it, but for the storys i have heard about long term use and the problems its caused, i wouldnt do it.

[CBFryman]

water isnt an element, and it is only hard/almost imposible to compress in liquid form. not when it is a gas.
Long term use...probably shows more benefits in a proper system than downfalls, if yo uuse an ethanol mix ethanol murns cleaner and cooler and the steam helps keep the combustion chamber free of debris and soot. no your not going to rust anything so dont try that approach either.
Putting race gas in your WI system will do nothing for you. it will probbaly make your engine stall from running too rich. if you want to use race gas put it in your tank...but there is no point in "race gas" if the engine isnt built to utilize the power from it...unless its nitromethane mix in which case running any mroe than 5-10% mixture with 112 leaded or Ethanol expect to kill something. spin a bearing, throw a rod, excetera. unless your engine is built for nitromathane in which case you are compeating in top fule or funny car...and you wouldnt be asking that question, espeically on AF.com.

[kachok25]

Originally Posted by CBFryman

water isnt an element, and it is only hard/almost imposible to compress in liquid form. not when it is a gas.
Long term use...probably shows more benefits in a proper system than downfalls, if yo uuse an ethanol mix ethanol murns cleaner and cooler and the steam helps keep the combustion chamber free of debris and soot. no your not going to rust anything so dont try that approach either.
Putting race gas in your WI system will do nothing for you. it will probbaly make your engine stall from running too rich. if you want to use race gas put it in your tank...but there is no point in "race gas" if the engine isnt built to utilize the power from it...unless its nitromethane mix in which case running any mroe than 5-10% mixture with 112 leaded or Ethanol expect to kill something. spin a bearing, throw a rod, excetera. unless your engine is built for nitromathane in which case you are compeating in top fule or funny car...and you wouldnt be asking that question, espeically on AF.com.

So how mutch additional compression/boost would I be able to run with a 30%ethanol 70% water injection do you think?

[CBFryman]

depends 100% on the engine and what tuning is done to it. It isnt always so much that you can run more boost as it is the more dence air with the same boost along with the added safety.
Take the Tiburon V6 for example.
Stock they have about 150whp
With a supercharger at 9psi that figure more than doubles. All they do is tune it, boost it, and add WI. with out the WI they wouldnt be able to have as aggresive tuning, this along with the WI itselft wouldnt let it make as much power, and it wouldnt be as safe.

[-Jayson-]

water injection is a great tool. Its not a tool for a badtune, its a form of cooling, just like an intercooler. I plan on running a water injection kit when my warranty expires. Ive done alot of reading on it and am well aware of its abilities.

No one can tell you for sure how much extra boost you will be able to add with water injection, it all depends on the engine and setup. Most of the time water injection is used to cool superchargers that are creating excess amount of heat due to smaller pullies. If you got a turbo, just buy an intercooler, it will be alot easier to use.

With water injection you need a water tank, usually its mounted in the trunk. You have to keep the tank filled otherwise no more cooling effect, lots of knock and possible engine damage.

The water is spayed as such a fine mist that it doesnt effect the engine. It wont rust parts, cause the engine to hydro lock, or anything like that. A good water injection kit will nearly atomoize the water particles as they are spayed into the intake.

www.coolingmist.com is a really good place for water injection kits.

Also id suggest running a 50/50 mix of water and pure alcohol. The alcohol can absorbe more heat than water alone and its also combustable.

[Reed]

sorry for my ignorance but why cant you just inject 100% pure alchohol? Seems like it would cool more or would it heat more since it will all be burning?

[kachok25]

Originally Posted by Reed

sorry for my ignorance but why cant you just inject 100% pure alchohol? Seems like it would cool more or would it heat more since it will all be burning?

You can run 100% alcohol and it does make more power, and it does increase the effective octane rating of your fuel. the problem is that pure alcohol raises engine temps since it carries so much oxygen in with it. The rule is that anything more than a 50/50 mix raises engine temps, so it is not usualy recomended.

[kachok25]

Hey yall I just found somthing REALLY intresting check this out.


Some aviation SI engines still use boost fluids. The water-methanol mixtures
are used to provide increased power for short periods, up to 40% more -
assuming adequate mechanical strength of the engine. The 40/60 or 45/55
water-methanol mixtures are used as boost fluids for aviation engines because
water would freeze. Methanol is just "preburnt" methane, consequently it only
has about half the energy content of gasoline, but it does have a higher heat
of vaporisation, which has a significant cooling effect on the charge.
Water-methanol blends are more cost-effective than gasoline for combustion
cooling. The high Sensitivity of alcohol fuels has to be considered in the
engine design and settings.

Boost fluids are used because they are far more economical than using the
fuel. When a supercharged engine has to be operated at high boost, the
mixture has to be enriched to keep the engine operating without knock. The
extra fuel cools the cylinder walls and the charge, thus delaying the onset
of knock which would otherwise occur at the associated higher temperatures.

The overall effect of boost fluid injection is to permit a considerable
increase in knock-free engine power for the same combustion chamber
temperature. The power increase is obtained from the higher allowable boost.
In practice, the fuel mixture is usually weakened when using boost fluid
injection, and the ratio of the two fuel fluids is approximately 100 parts
of avgas to 25 parts of boost fluid. With that ratio, the resulting
performance corresponds to an effective uprating of the fuel of about 25%,
irrespective of its original value. Trying to increase power boosting above
40% is difficult, as the engine can drown because of excessive liquid [110].

40% extra power sounds good to me, I might not be able to quite reach that number because but even if I hit 20% water injection would be a well worth while investment.

[kachok25]

Cool Here is another intresting tid bit I found online. I have noticed that ALOT of land speed record holders use water injection, is there somthing about extreamly high speed that makes it better? The only thing I can think of is the fact that they run so much hp for such a long ways, maby they have to have somthing for the extra cooling. I saw the land speed record for a motorcycle also and he was using water injection as well.

2/7/05 234 MPH! 911 Porsche uses Boost Cooler® to set World Record!

Der Chef rast selbst: 9ff-Chefingenieur Jan Fatthauer (links, neben Ralf Rossenbach von Continental).
Ein Porsche 911 vom Tuner 9ff hat einen neuen Geschwindigkeitsrekord für straßenzugelassene Fahrzeuge aufgestellt – 388 km/h.

Jan Fatthauer has just set the record for the World’s Fastest 911 Porsche using a Stage-2 Boost Cooler®. This car reportedly not only injected water/methanol but sprayed the intercoolers as well. See www.autobild.de for full details.

[kachok25]

Racetech inc has a mention of it on their tech page that is really intresting.

My personal experience with water injection is considerable. I had several turbo cars fitted with it. One 2.2 liter Celica with a Rajay turbo, Weber carb and no intercooler or internal engine mods ran 13.3 at 103 on street rubber on pump gas back in 1987. This was accomplished at 15psi. With the water injection switched off, I could only run about 5 psi before the engine started to ping. I think you might see water injection controlled by microchips, catch on again in the coming years on aftermarket street turbo installations. It works.

I recomend that anyone that is into forced induction engines read this article it is VERY informative, It is not actualy about water injection but about octaine, compression, and timing and there effect on power. He even breaks down the different setups made power. Great article. http://www.sdsefi.com/techocta.htm BTW that little stock internal, street rubber, non-innercooled, FWD, carburated, pump gas, 4 banger will outrun a modern LS1 V8 Camaro, Mustang GT, several of the Corvettes, any musclecar in stock trim, and most of the new hot japanese imports. That is absolutly crazy! Now imagine what they could do with a modern computer controled water injection system, this could get really intresting. If yall find any intresting links on the subject or have any imput on it hit me back.

[beef_bourito]

why did you have a webber carb on a celica, i though they were efi. also it's alot harder to tune a carb for less gains so i don't see any advantage in switching to carb.

[kachok25]

Originally Posted by beef_bourito

why did you have a webber carb on a celica, i though they were efi. also it's alot harder to tune a carb for less gains so i don't see any advantage in switching to carb.

It was 1987 and prob a few years old then, it was carburated from the factory I am sure.

[kevinthenerd]

Originally Posted by CBFryman

Ethanol is not, in anyway, composed of oxygen.

I know this is an old thread, but I just had to correct this. Ethanol has the chemical formula C2H5OH. The presence of oxygen partly explains why the stoichiometric air/fuel ratio of ethanol is so low. Remember when Waltrip got caught with that "substance" in his intake manifold? An insider who wasn't supposed to say anything (and whom I definitely can't name here!) tome what it was. It was sterno, which is part methanol. All alcohols contain oxygen in their molecule (with that OH at the end). In restrictor plate racing, any bit of extra oxygen you can sneak in will give you an advantage.

I came to this thread wondering about water injection. I would like to use it to increase the power of a stock, naturally aspirated engine. This very same thing was done back in World War II to temporarily increase the power of fighter aircraft during takeoff.

I would like to inject the water as droplets, but if the water gets heat from the air, it would condense it, so that's fine too. I think it'd be best to serve the water from a chilled tank. Water has a high specific heat, especially when boiling, so it therefore would absorb a lot of energy inside of the combustion chamber if it comes to equillibium temperature. Boiling heat transfer, too, is very effective; the water can absorb this heat very quickly. This steam would put more pressure on the cylinder crown than the expansion of a gas alone.

That last paragraph was part speculation since I haven't sat down and worked out the math yet, but it is true that this was effective during WW2. I think part of the reason why it hasn't been studied further is its ban in much of motorsports. I think this would be great for bracket racing where you won't find as many regulations and where a sudden suprise of power is quite advantageous.

Edit: One more thing... Water in your engine will seep past the rings just like water from regular combustion. This water will chemically combine with your oil and form acid. Your oil will wear out quickly, and you should use an oil with a high TBN (total base number) and change it frequently.

Edit again: Sorry, the WW2 use of water injection was already mentioned here in the thread. Sorry for not reading that earlier: http://www.sdsefi.com/techocta.htm

[2.2 Straight six]

please don't bring back old threads.