Water Injection, declined in popularity, why??

[JohnA]

The pump is quite a bit noisier when it runs dry, so you'll probably hear that something is off before it overheats itself to death.

[bondango]

...as you should;)

This man may be an expert in a field or another, but not in this one.

His opinion therefore carries little weight

He makes simplistic assumptions (water puts out fire, doesn't burn etc...) without knowing how it really works.

But he thinks he knows, hence the 'foolish' bit:eyebrows:

 

Again, an uninformed opinion from a non-expert.

He assumed that chargecooling is what WI is all about.

Well it isn't. It is only a minor byproduct, practically negligible in the winter on a well setup car.

 

Just to add, WI isnt something new or something that can be dismissed as any enginneer knows - it was pioneered in the 40's by Authur Smith when it was first used on the Pratt & Whitney R-2800 "Double-Wasp” engines to give them an extra burst of power when needed.

 

http://en.wikipedia.org/wiki/Pratt_&_Whitney_R-2800

 

 

Just another piece of useless info from me lol

[JohnA]

Without WI I doubt that my engine would survive full throttle bursts of more than 5 seconds.

 

OK, it's not a representative example of turbo tuning, but it is proof that WI works.

 

It is like cooking using a bunch of exotic ingredients and in the end managing to make a pile of shite - not the ingredients' fault, is it?

They were used in the wrong recipe, that's all.

 

In the case of WI, most people do what they do tuning-wise (run it pig rich at full boost), then stick a WI nozzle at a convenient location and expect 'more power' and 'more reliability'

Well, that's how you lose power.

[toyo rob]

Just to add my two p's.....

 

just got back from CW's today, must say a huge thanks to him for a short notice booking then still letting me in when i'm late!!!,

he just fitted wi on my bpu...

 

and what a difference, she's been running a bit funny, odd occasions where she seems to start overfuelling when i keep my foot steady on the pedal,

 

well whether the wi fixed it or is hiding it i dont really care as i've already had a beautifully smooth ride home, also my old boost settings went right out the window as i was boosting through the roof on what was 1.1 ended up reducing the boost setting by 10% easy and on top of everything else she seems to be doing nearly 50 extra km's per tank, (based on 125 from full to 3/4's constant to 150, then a bit of maths!!)

[Kim1978]

bumping this thread as I am looking into water injection as well.

 

Anyone else here with good experiences?

 

cheers,

 

Kim

[bignum]

Yes, had mine fitted this summer and seems good, engine picks up better and pulls right through to redline.

[gaz1]

bumping this thread as I am looking into water injection as well.

 

Anyone else here with good experiences?

 

cheers,

 

Kim

 

not yet but i have a kit waiting to get fitted;)

[magictorch]

I will be fitting WI on mine when i decide which kit to go for...

[ajazyasin]

so, is the best place for fitting the nozzle in front of the TB?

[Wez]

Just before the throttle is fine, another popular location is just after the IC.

 

After the IC would offer better charge cooling as it has more time to mix, just before throttle would offer better in cylinder cooling.

 

EDIT: mine is just before the throttle

[ajazyasin]

cool.

thanks:)

[Durandal]

I used to think that water/meth kits were a cheap/messy/complicated way to increase performance until I did a lot of reading about it. I think that most people who aren't familiar with it are of the "put water in engine = bad" thought pattern.

 

Are there any kits around for supra fitment with pipe for injection point that fits in between the throttle body and IC piping? I would like to add this soon but am bouncing between brands as I want something that looks clean and works well.

[Swampy442]

Holy thread resurection!

[Durandal]

Yah my bad, I was thinking this was on the front page without looking at the dates, but it was from search

[Swampy442]

Think it shows how water injection has been overtaken by higher quaility fuels and better mapping

[a98pmalcolm]

I have AEM water injection and i dont see it as a waste.. Worth every penny on those hot days it helps out.

 

I think Water injection isnt shown up enough to let people realise what it does or even if it exists!

[Chris Wilson]

The basic ERL kit will do all you wish, with no great complications. I have sold and fitted dozens of these. I personally have seen, on my own car, a 20 degree c reduction in intake charge air temps with these systems. i would rarely run a turbo engined car without WI these days. this may help:

 

Water injection serves 2 closely related functions on a turbo engined

car. Firstly it cools the charge air temperature by utilising an effect

known as the latent heat of evaporation. This property can be self

demonstrated very easily. If you pour something that evaporates quickly

like petrol on your hand it feels very cold. This is the rapidly

vaporising spirit removing heat from your skin and bloodstream by the

aforementioned process. By spraying a very finely atomised mist of water

into the inlet of a turbo engine when under boost conditions the

evaporation of the water into steam causes a temperature reduction in the air and

fuel intake charge. A cold charge is less likely to be subject to

detonation than a hot charge. A cool charge is also denser, able to

carry more air and fuel mix per unit of volume. These 2 properties of

water injection allow either less chance of detonation at a given boost,

maybe allowing lower octane fuel to be used, or to allow a rise in boost

pressure usage without detonation. These are very desirable goals for

any modifier of a turbo engine, or one using an engine mapped to run

on a higher octane fuel than generally available in the UK. Japanese

import turbo cars for example.

 

People ask whether squirting water into an engine causes corrosion. In

fact this is not a problem, the combustion temperatures under boost

ensure the water is turned instantly to steam and is ejected out of the

exhaust. The water mist is injected only when high boost is sensed via

a supplied pressure sensor switch. The basic combustion process of

hydrocarbon fuels causes LOTS of water to be generated anyway, which is why cars

not driven on regular long journeys will rust out a mild steel exhaust

system from the INSIDE out. If water is added in the correct volume, via

the supplied, calibrated jets, this is not a problem.

 

Even when used alongside a larger or more efficient intercooler, or

indeed when an intercooler is used in an application where one was not

present as standard, water injection can and does increase charge cooling

still further. Water can be stored either in the existing windscreen

washer bottle or in a separate, dedicated, container. In cold conditions

it is essential to add an anti freeze additive to the water to stop pump

damage through freezing. Windscreen washer additive serves this purpose

fine and the engine won't mind ingesting this solution at all. Or you

can add neat methanol, which is usually the anti freeze additive in

washer fluid anyway. Using a 50 / 50 percent by volume water / methanol

mix will actually help increase the octane of the intake charge, as an

added benefit. As a yet further advantage the latent heat of evaporation

of methanol is extremely high. A win / win situation. It is not however

obligatory to use methanol as an additive. All components of the water

injection kit that are in contact with the fluid are stainless steel or

able to tolerate water and methanol or screen washer additive without

degradation. A properly set up system does not use a vast amount of

water, in fact a modern car sized screen washer bottle used also for the

water injection reservoir will suffice admirably. A water filter is

included to keep any sludge out of the pump or jet. This should be

checked regularly for contamination and blown out if residue is

apparent within.

 

A more technical explanation:

 

Let us take a quick look at ignition. Those who have a Heywood can look it up

- mines on loan so going by memory. The first thing that happens is a plasma

cloud is formed by the arc consisting of super heated electron stripped atoms.

When this cloud "explodes" a ball of high energy particles is shot outward.

 

The highest energy particles are the hydrogen atoms - and they penetrate the

charge about 5 times as far as the rest of the particles. As they lose energy

and return to normal temps - about 5000 k - they begin to react chemically

with any surrounding fuel and oxygen particles. The effectiveness of spark

ignition is directly related to the availability of free hydrogen. Molecules

containing tightly bound hydrogen such as methanol, nitromethane, and methane

are far more difficult to ignite than those with less bonds.

 

During combustion - water - H2O ( present and formed ) is extremely active in

the oxidation of the hydrocarbon. The predominate reaction is the following:

 

OH + H ==> H2O

H2O + O ==> H2O2

H2O2 ==> OH + OH

Loop to top and repeat.

 

The OH radical is the most effective at stripping hydrogen from the HC

molecule in most ranges of combustion temperature.

 

Another predominate process is the HOO radical. It is more active at lower

temperatures and is competitive with the H2O2 at higher temps.

 

OO + H ==> HOO

HOO + H ==> H2O2

H2O2 ==> OH + OH

 

This mechanism is very active at both stripping hydrogen from the HC and for

getting O2 into usable combustion reactions.

 

Next consider the combustion of CO. Virtually no C ==> CO2. Its a two step

process. C+O ==> CO. CO virtually drops out of early mid combustion as the O

H reactions are significantly faster and effectively compete for the available

oxygen.

 

Then consider that pure CO and pure O2 burns very slowly if at all. Virtually

the only mechanism to complete the oxidization ( Glassman - Combustion Third

Edition ) of CO ==> CO2 is the "water method".

 

CO + OH ==> CO2 + H

H + OH ==> H20

H2O + O ==> H2O2

H2O2 ==> OH + OH

goto to top and repeat.

 

This simple reaction accounts for 99% + of the conversion of CO to CO2. It is

important in that fully two thirds of the energy of carbon combustion is

released in the CO ==> CO2 process and that this process occurs slow and late

in the combustion of the fuel. Excess water can and does speed this

conversion - by actively entering into the conversion process thru the above

mechanism.

 

The peak flame temperature is determined by three factors alone - the energy

present and released, the total atomic mass, and the atomic ratio - commonly

called CHON for Carbon, Hydrogen, Oxygen, and Nitrogen. The chemical

reactions in combustion leading to peak temperature are supremely indifferent

to pressure. The temperatures and rates of normal IC combustion are

sufficient to cause most of the fuel and water present to be dissociated and

enter into the flame.

 

As can be seen above, water is most definitily not only not inert but is a

very active and important player in the combustion of hydrocarbon fuel.

Ricardo and others have documented that under certain conditions ( normally

supercharged ) water can replace fuel up to about 50% and develop the same

power output, or that the power output can be increased by up to 50% addition

of water. This conditions were investigated by NACA and others for piston

aircraft engines. It is important to note that these improvements came at the

upper end of the power range where sufficient fuel and air was available to

have an excess of energy that could not be converted to usable pressure in a

timely manner.

 

As a side note - Volvo recently released some SAE papers documenting the use

of cooled EGR to both reduce detonation and return to a stoic mixture under

boost in the 15 psi range - while maintaining approximately the same power

output. Notice - they reduced fuel and still get the same power output.

 

When you consider that EGR consists primarily of nitrogen, CO2, and water ( to

the tune of about two gallons formed from each gallon of water burned ), you

might draw the conclusion that it also was not "inert". They peaked their

tests at about 18% cooled EGR - which would work out to about 36% water

injection and got about the same results under similar conditions that the

early NACA research got.

[Ian C]

I've had a trick ERL system sat for about 4 years in a box at home, I've not found time or the need to fit it, in fact I hardly have driven the car with with other personal life commitments I've been up to. Seeing as the car runs fine without it, it's hard to justify the hassle. However I might do it just for the hell of it now

[JamieP]

I removed mine, it did nothing for my car except made it feel slower.

[b_have]

One of the first things I fitted. Ryan often comments how low my IATs are when mapping.

[JamieP]

One of the first things I fitted. Ryan often comments how low my IATs are when mapping.

 

Did i not read you had the sensor in the IC pipe though? do the temps go up if you turn it off? made no difference at all to my intake temps.

[b_have]

Yes, the sensor is just before the TB in the ic pipework. I used to have two injectors, one post ic and the second into the TB but now back to just the TB location.

Ive never tested without so have no numbers but maybe this together with Ryans mapping is the reason my 4088 looks mint every time it's checked.

[JamieP]

That will be while the temps are low, minimal heat soak in the ic pipe, on a different note, as ive gone bigger turbos over the years both my intake temps and egt's have lowered each time the turbo got bigger.

[sdistc]

I just wonder if the environmental conditions over here are the main cause - it rarely gets over mid 20s, it seems, and then only for the later part of the day.

[imi]

im going to set mine this afternoon to come on at 12 psi and full open at 22psi. See how long the 5ltrs of 50/50 mix lasts.

 

every little helps as they say.