AEM water injection install

[imi]

I cant see a benefit in that tbh, if the engine is not running hard enough then a load of water pumped in cant be good surely.

 

when i am driving in heavy traffic and the air temps get high (summer - 60C +) a quick squirt here and there could reduce the temps....or should reduce the temps.....if people dont think it is worthwhile then i wont bother.

[JamieP]

when i am driving in heavy traffic and the air temps get high (summer - 60C +) a quick squirt here and there could reduce the temps....or should reduce the temps.....if people dont think it is worthwhile then i wont bother.

 

I dont think that will work, with the engine not pushing much revs or air the water will just drop down and sit in the bottom of the ic id have thought.

 

Interchiller kit may be your answer.

[imi]

I dont think that will work, with the engine not pushing much revs or air the water will just drop down and sit in the bottom of the ic id have thought.

 

Interchiller kit may be your answer.

 

Thats a fair point there Jamie.....

[Tricky-Ricky]

Just for the record, water injection will make no difference to performance unless it is mapped in with the tuning, IE advanced timing beyond normal parameters, and or fuel leaned out to slightly below safe levels, this takes a lot of work and you will need lots of safety features in place to avoid a meltdown.

 

Its best used for charge cooling and in cylinder cooling to help prevent detonation, also adding meth will not make a difference unless its pure meth, and then its not much as in proportion to the whole combustion process, so it would be unlikely to show any real increase on the dyno.

 

However on a hot day, if the proportion of water is correct, you will notice the engine feel more urgent than without it, but to get the best from WI it really needs to be mapped.

 

Oh and yes if you just squirt water into the engine you will more than likely loose power.

Edited January 11, 2009 by Tricky-Ricky (see edit history)

[dangerous brain]

On a car with adequate fuelling you won't notice that huge a difference with water meths. It comes into its own when you push your fuel system to its limit. When you tune it so your AFR's are so marginally dangerous WI will make a huge difference. If however your fuelling is OTT then you can bung some extra fuel in to keep it safe as opposed to needing WI. WI really does make a massive difference on J-spec motors that are pushed up to 1.1 bar and beyond where the fuel is only mapped up to a bar.

[L33]

looks very good mate well done and going to sound stupid now but whats EGT and AFR?

Edited January 11, 2009 by L33 (see edit history)

[Chris Wilson]

EGT = exhaust gas temperatures. Here's a little article I wrote a few years back, plus some other info. I have also just been reading (this morning, as it happens...) about research GM did into water injection, but I haven't got it in electronic format (SAE paper I bought).

 

 

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.

[L33]

cheers, little article :blink:

[imi]

Mine is just placed halfway between the pump and the nozzle.

 

Hey buddy.

 

I see that you have your NPV mounted between the pump and nozzle. does it make better sense to have it between the tank and the pump in order to prevent syphoning?

[dangerous brain]

Hmmm interesting thought. I will say I honestly don't know.

[salihbjk]

can't you use 100% meth with this kit?

[Jellybean]

How does the kit know when the turbo's are at X bar and water meth is required? Is it wired into the ECU?

[Chris Wilson]

Most of the basic kits use a simple pressure switch plumbed into the plenum to turn them on or off. My dislike with kits based on crop sprayer pumps is they don't normally generate enough pressure for perfect atomisation.

[Jellybean]

Cool Thanks Chris!