methanol

[JamieP]

is this the right stuff for my water injection?

the bio diesel bit is getting me thinking it might not be:)

http://cgi.ebay.co.uk/Biodiesel-Methanol-bio-diesel-99-5-purity-205L_W0QQitemZ9507224148QQcategoryZ26261QQtcZphotoQQrdZ1QQcmdZViewItem

[JamieP]

another

http://cgi.ebay.co.uk/Biodiesel-Methanol-bio-diesel-25L-99-5-purity_W0QQitemZ9506172071QQcategoryZ26261QQrdZ1QQcmdZViewItem

[JamieP]

bttt, someone must know if this is the right stuff?

[Tricky-Ricky]

TBH i'm not sure, i get mine from a model shop, the stuff without any additives, you only need a 20% mix so 5lt will last for ages, tip you will not gain anything by adding more, at more than 30% you will actually start to detract from the effects of using water injection, take a look on the water injection forum.

[JamieP]

ahh model shop, didnt think of that

thanks for the advice ricky

[JohnA]

Only use pure methanol --- and remember that mixed with water at over 50% it is flammable.

[ChrisSZ]

also remember that if you inform the seller that it is to be used to power a mode of transport then they are duty bound to add on fuel tax!!!!

[JohnA]

True.

It is always for your RC Supra model.

(scale 1:1)

[JamieP]

True.

It is always for your RC Supra model.

(scale 1:1)

[b_have]

Will be expensive from model shops, also if for RC use it will have castor oil in it (VERY bad for injector gumming).try yellow pages -Chemical suppliers. I pay around £1.50 a litre.

[ChrisSZ]

I paid around 90p/l from a model shop for pure methanol (bring your own container).

[JamieP]

thanks for the advice guys

[JohnA]

Yep, £8 bought me two gallons.

At 20-30% mix it lasts long. Remember that it only injects when you are over a boost threshold, 1 bar or so.

It's not easy to go through 300ml of methanol even during a very hard drive out. Speeds get very silly, very quickly.

[JamieP]

Yep, £8 bought me two gallons.

At 20-30% mix it lasts long. Remember that it only injects when you are over a boost threshold, 1 bar or so.

It's not easy to go through 300ml of methanol even during a very hard drive out. Speeds get very silly, very quickly.

so is 1 bar the recomended time to set it to come on?

[JohnA]

so is 1 bar the recomended time to set it to come on?

It depends on the rest of the setup as well as external temps and style of driving.

I've seen gains on the dyno from as low as 0.6bar, but for various reasons wouldn't fix mine below 1 bar.

[gregsupra4]

Water injection (and water mixtures like mixed methanol injection) has been around for decades. Its sole purpose is to suppress engine knock. Keeping in mind that most engine knock is caused by uncontrolled and/or unintended combustion of the fuel mixture. Water with it high specific and latent heat is an excellent tool for bringing charge temperatures and combustion back into control when charge and cylinder temperatures or compression get too high for the fuel being used.

 

Water is generally introduced to the induction system after the turbo-charger and before the throttle body.

It may be injected pre- or post-intercooler or both.

 

The injection of water into the induction charge will immediately absorb heat from the charge thereby increasing its density. Evaporation of the water at this point is unlikely or very minor.

The induction charge can at a maximum reach 100% relative humidity and will stabilize at an equilibrium state that is governed by temperature of the charge exiting the turbo and the relative humidity of the ambient air. At full saturation the induction charge will have a significantly reduced temperature somewhere between the ambient temperature and the temperature of the injected water. This heat absorption is achieved primarily through the water's specific heat very little vaporization will occur at this point. The boiling point of water is higher than most charges exiting the turbo and the cooling effect of the water will reduce even the hottest charges without significant vaporization and never beyond the point of saturation and equilibrium.

 

The effect of water on the induction charge will be somewhat greater in drier climates where more water can be evaporated into the air.

However this should not be taken as an indication that it is not useful in more humid climates. Once the induction charge gets heated it will always have room to accept the evaporated water whether the initial relative humidity was high or low - and this evaporation will always absorb heat from the induction charge.

 

As the water absorbs heat the droplet sizes will decrease and the surface area of the water droplets will increase. Any additional volume from this reaction will be more than made up for by the reduction of the charge temperature and its resulting increased density. Water is not displacing the volume or weight of air in the induction charge and actually working to increase the volume and weight of air that reaches the cylinder. Sizeable droplets of water will reach the cylinder with significant heat absorbing potential intact.

 

The cooling of the induction charge is the first way that water injection suppresses knock and permits more air-fuel mixture to enter the cylinder.

 

During the intake stroke as the induction charge passes the valve the charge picks up heat from the heated surface of the intake valve. Additionally the effort of sucking the charge past the valve transfers heat to the charge as well. The presence of water in the induction charge absorbs this heat more readily with a lower increase in the temperature of the charge. Remember that it takes more heat to increase the temperature of the water present in the charge. Air and fuel alone in the charge increases in temperature much more readily and rapidly as it absorbs the heat from the valve and effort exerted to bring the charge into the cylinder.

 

Once the charge enters the cylinder, water in the induction charge following the exit of the super heated exhaust gases (1500+ degrees) begins to immediately cool the surfaces within the cylinder including the cylinder walls, piston head, combustion chamber, valves and spark plug tip. This cooling will have its most dramatic effect on any possible hot spots the coolant system has not adequately addressed. Surface temperatures will be significantly reduced by the water even more so than the extra fuel that was previously being used to cool the cylinder surfaces.

 

With twice the specific heat and six times the latent heat of gasoline, 1/6 as much water by weight is necessary to fully replace the heat absorption of the decreased gasoline in the induction charge. Richer than 12:1 none of that extra fuel is being burned in combustion and the extra fuel robs significant power while serving as a poor coolant. Since the amount of water being added is only a fraction of the amount of the decrease in gasoline there is actually more air and as a result more oxygen in the induction charge for additional combustion to take place.

 

 

The cooling of the cylinder area surfaces permits additional air/fuel mixture to enter the cylinder thereby increasing volumetric efficiency. The combination of decreased liquids in the induction charge combined with the increased VE from in-cylinder cooling disproves the myth that water injection will displace air in the induction charge or reduce the amount of fuel that will be burned in combustion.

 

During this process the continued absorption of heat will decrease the water droplets further increasing their surface area and volume but full vaporization accompanied by the resulting 1700 times increase in the volume of the water will not have occurred at this point. The water will still reach equilibrium prior to this point, albeit in a hotter state.

 

The absorption of the heat gain while actually entering the cylinder and the cooling of the cylinder area and volume is the second way that water suppresses knock - the cylinder and the charge is much better prepared for a controlled burn during combustion.

 

By this time water has lodged itself between the air/fuel mixture although the percent of water to the mixture is only around 1%. Though the ratio is small the water further suppresses any remaining tendency of the fuel to pre-ignite by lodging itself between the air and fuel during compression. Before actual combustion occurs the water works against auto-ignition by continuing to absorb the heat generated during compression.

 

Water is a byproduct of combustion it is the chemical reaction of oxygen with the hydrogen freed from the hydrocarbon chains during combustion. How could the injection of additional present water before combustion contribute further to the combustion process? This is where it gets a bit complex and I will try to do the best I can.

 

During early combustion when the fastest reactions occur the effect of the water in the mixture is to cause a more controlled and stable flame front. The freeing of hydrogen and carbon to combine with oxygen has to work around the present water to form OH radicals and CO. By slowing this early combustion process there is further suppression of the potential for the mixture to burn too fast and contribute to knock.

 

Later in the combustion process slower and more complex reactions occur. The formation of OH radicals is very fast and interferes with the completion of the combustion process to form CO2 from the first step creation of CO. It is during this phase of combustion where present water helps to complete the slower reaction to complete the formation of CO2 since water is about the only way to complete the oxidation of CO. The additional present water actually speeds this reaction which also happens to be when as much of two thirds of the energy from carbon combustion is released.

 

It is apparent that in any hydrocarbon oxidation process CO is the primary product and forms in substantial amounts. However, substantial experimental evidence indicates the oxidation of CO to CO2 comes late in the reaction scheme. The conversion to CO2 is retarded until all the original fuel and intermediate hydrocarbon fragments have been consumed.

 

Performance tuning that involves fuel dumping necessitates overly advanced timing resulting in timing induced knock (and as has been experienced by others engine destruction) because the significant power release from combustion is delayed to the point where MBT is very late while waiting for the excess fuel is broken down during the extended initial stages of combustion. In upgraded turbo applications this becomes extremely apparent as the increased air flow necessitates ever higher fuel flows to maintain these supposedly safe AFRs of 11:1 and richer.

 

More simply consider the following - what power enhancing purpose would excess fuel serve once all the oxygen in the induction charge has been utilized in combustion? It can not and will not burn, Glassman has shown that it even interferes with the complete combustion of the fuel that is burnt. It is only useful as a coolant and most fuels make poor coolants.

 

As illustrated below water injection can actually help reduce maximum cylinder pressures while increasing BMEP. This is because a properly mixed AFR of 12.5:1 accompanied by water injection increases the rate of the combustion reaction exactly when it is desirable to do so during the oxidation of CO => CO2.

 

 

SEE ATTACHED GRAPH

[gregsupra4]

Some water injection users have used significantly higher water to fuel ratios (25%+). The technique usually involves increasing water flow until the engine bogs down or comes close to misfiring then pulling back a little bit, before leaning the AFR significantly and finding the MBT advance needed. These techniques take significant amounts of experience and are less compatible with most street setups.

 

Average street uses should try and target 10%-15% water to fuel. Aggressive street and moderate track use can pretty readily utilize as much as 25% water to fuel especially when using a mixed methanol injection system.

 

In general water injection and mixed methanol injection not only permits advancing timing, it is required due to the slower initial flame front (though late stage reactions are sped up) during combustion. This is contrary to many nitrous techniques so great care and skill must be employed to find the appropriate balance when trying to use both water and nitrous to make significant power gains.

 

When adding 5%-7% water to fuel without leaning rich fueling levels - a degree or two of advance will produce almost the same power result as without water injection (leaning slightly will increase the power output). This is good for people who have engines tuned for high octane or race fuel but on a daily basis want to use lower octane grades. This is purely an economic use of water injection - power use requires fuel and timing tuning.

 

The more boost you are running and the more fuel you are replacing with water injection the more dangerous it becomes to run a constant pressure / static flow water injection system. In order to prevent bogging down the engine at lower boost loads the flow of water is less and less likely to be sufficient for your full boost application in these static setups.

 

The state of your air/fuel mixture and timing after performance tuning for water injection or mixed methanol injection will be more than sufficient to destroy your motor if the water injection fails while under load. The responsible user will take measures to ensure adequate water is in supply and flowing during high power usage. Ideally along with a fail safe that will cut boost if a fault in the system occurs. At a minimum warning lights for water level, water pressure and water flow should be employed. Ideally triggers that close all boost solenoids in automatic response to faults would be employed by high end systems.

 

Have fun

[Muffleman]

I tried to buy some from a local RC shop and they said that they aren't allowed to sell pure methanol anymore ?!? Is this bullplop ?

 

Let me know where you get yours from Jamie, I need some for the MR2.

 

Cheers

 

 

Matt

[JohnA]

Water injection (and water mixtures like mixed methanol injection) has been around for decades. ...

...alternatively you could have posted a link to the water injection forum:)

This is an extract from one of the white papers posted there.

[terribleturner]

I must say i'm quite tempted by this now. Maybe i'll get the car set up and dyno'd, then get a kit and dyno again to see what happens.

[Tricky-Ricky]

Just to reiterate, if you are considering water injection, don't think you can just add a pressure activated WI system and expect to see instant performance gains! it certainly won't do any harm! but in order to extract real gains you will need to be able control timing and fuelling, and ideally use an Aquamist system that can also be mapped! the 2C is ideal for use with the blue Emanage as you can use the sub injector output to map water injection along with being able to control the ing and fuelling, but remember you will need to use some sort of water flow detection and preferably a way to at least cut boost should a water blockage,shortage occur! or you could be looking at a rebuild:(

[Wez]

So where are people getting there Meths from then?

 

Is there an online place, maybe one of the suppliers on here could go into the chemical supply business

[JamieP]

you can buy it here but its expensive

http://www.motorshack.com/acatalog/VP_Methanol_and_Nitromethane.html

[Lucifer]

We are stocking this now. £25 per 5 L.

[Wez]

We are stocking this now. £25 per 5 L.

 

Roughly how long would 5L last on a 50/50 mix which is only active say above .8bar.

 

Just trying to figure how big my water/meth tank should be