Lets Talk Water Meth Injection

[abr33]

Haha, I will mix by volume id imagine?

I always bought it as it was simple and easy

[blue_vl_t]

Is there some reason why using straight methanol is not talked about. A local I know runs a supercharged ls2 on 98 with straight methanol, the guy he bought the kit from in America said methanol is higher octane and has better cooling effect than Water, so why would you want to mix it? Fair point I think. What am I missing?

[The Mafia]

I'm pretty sure that water absorbs more heat than methanol.

Someone needs to break down what each substance does - ie what the water does and what the methanol does.

[Ben C34]

Definitely reasons for and against everything!

When mixed 50 50 it is not going to burn if leaked into engine bay.

Straight meth is more dangerous, and should be in a proper fuel cell

Water is better at detonation suppression.

It gets very scientific very quickly!

[abr33]

Also the pumps dont like running straight methanol for extended periods of time. And yes id be scared to have 15L of methanol in the boot. I havent yet tried burning the 50/50 mix though. Methanol in confined space, with battery and relays etc etc is a recipe for a bad time

[blk94r33]

Also straight methanol injection will not cut out with a rev limiter, so the engine will try to run on an excessively lean mixture.

[GOD12A]

Heya guys,

Just a quick note from my experience.

I remember from my rotary/N2O days, we used to run a separate fuel system for the N2O running straight methanol (N2O likes low fuel pressure at the nozzle, so EFI cars ran a low pressure system for N2O only)

A reasonable amount of these engines would eventually let go when the tune was squeezed.

I believe the different burn rate and temperature between the straight methanol and 98RON mixing inside the combustion chamber made tuning difficult.

If you can imagine there's two different combustion stages when two very different fuels are mixed in the combustion chamber.

Most of the 'big guys' in the rotor/N2O scene ended up using the same fuel for their EFI and N2O fuel systems in the end.

Hope it helps.

Mark

[Rolls]

I'm pretty sure that water absorbs more heat than methanol.

Someone needs to break down what each substance does - ie what the water does and what the methanol does.

I've asked this many times without a good answer, water cools better than methanol so I never understood why it is used, obviously methanol burns as well but I don't really see the issue of just using water.

edit:

http://www.aquamist.co.uk/vbulletin/showthread.php?t=1801

Apparently if using large amounts of injection if you use just water you can blow the flame out, if you start titrating it with methanol you increase the total amount of liquid you can inject before causing a misfire.

Eg if x ml/min of pure water is the max you can run before a misfire, if you use 50:50 you can inject x + y ml/min, you'll have slightly less heat absorbed per unit of liquid, but total heat absorbed will be greater due to being able to use more volume.

Makes sense.

Edited December 26, 2013 by Rolls

[Ben C34]

I'm with you. You nearly lost me with titrate though!

[RB_purr]

Who in Queensland fits WM kits ? Preferably Gold Coast end

[sucram]

Methanol and Ethanol increases the octane, water reduces pre ignition.

Water absorbs more heat then methanol.

So if you ran meth only, any addition timing is basically from increased RON. You basically

have a methanol enrichment system.

If you run water only, your stabilizing your mixture that would normally be done with richer mixtures,

So when running water/meth you usually go up a size or so.

I mix 50:50 by weight. I cant remember why but it works out to be more meth by volume. Even though you spray

volume, something something volume mass and density comes into the mix. Sorry about being vague, I forgotten

the formula, google it if you need to know more

[discopotato03]

Well water has a greater density than methanol so it has to weigh more per unit volume that water .

I think the methanol is there to counter the fact that water doesn't burn and its vapour pressure is lower so it vaporises more readily .

Evaporative cooling is partly why alcohol fuels work so well when combustion conditions get evil , approximately 1/3 more fuel going in with say E85 so more to evaporate and cool . Even more so with methanol which is supposed to have less than half the heat value of petrol . So I expect more than twice the volume going in than petrol and vaporising .

If you work out the octane rating of methanol and then water (0) and add them together (ie 50 50) you get an idea of the octane rating of your anti detonant fluid .

If you get 65-70 then I think you can assume that the volume of WMI being injected compared to the volume of fuel being injected may not be that high and if you then halve or whatever that for methanol content can you imagine much octane boosting going on ?

Seems to me that charge/combustion cooling is the main gain here .

A

[Dan_J]

I've asked this many times without a good answer, water cools better than methanol so I never understood why it is used, obviously methanol burns as well but I don't really see the issue of just using water.

edit:

http://www.aquamist.co.uk/vbulletin/showthread.php?t=1801

Apparently if using large amounts of injection if you use just water you can blow the flame out, if you start titrating it with methanol you increase the total amount of liquid you can inject before causing a misfire.

Eg if x ml/min of pure water is the max you can run before a misfire, if you use 50:50 you can inject x + y ml/min, you'll have slightly less heat absorbed per unit of liquid, but total heat absorbed will be greater due to being able to use more volume.

Makes sense.

one would think an upgraded ignition system would allow one to use more water. discuss ?

[jet_r31]

correct, but it comes down to many factors, how much power your making,how much

volume of fluid you used , and the variance of standard

style ignition systems on each vehicle to start with

cheers

darren

Edited February 2, 2014 by jet_r31

[Rolls]

Methanol and Ethanol increases the octane, water reduces pre ignition.

Water absorbs more heat then methanol.

So if you ran meth only, any addition timing is basically from increased RON. You basically

have a methanol enrichment system.

If you run water only, your stabilizing your mixture that would normally be done with richer mixtures,

So when running water/meth you usually go up a size or so.

I mix 50:50 by weight. I cant remember why but it works out to be more meth by volume. Even though you spray

volume, something something volume mass and density comes into the mix. Sorry about being vague, I forgotten

the formula, google it if you need to know more

The only reason I can see to run meth is because you run into issues with ignition.

50:50 by volume would be more water as meth is less dense, density of methanol is 791g per L so you'd end up with 1.26x more water than meth.

Eg you mix by volume and use 1L of meth, 1L of water, you actually have 791g of meth and 1000g of water.

You can instantly see why water can evaporate more heat as well due to there just being more of it per litre, also methanol burns so it will add to the heat.

Basically water does a much better job of cooling than meth can.

Edited February 3, 2014 by Rolls

[asps91]

Have been reading through the thread and learned some interesting stuff! What injection kit would you guys recommend for an rb26 with a single gt3582r hoping to make high 300's just that little bit safer. Little confused which way to go but the aem kits look pretty good value. And where is the most beneficial place to put the injector/s?

[asps91]

http://www.alcohol-injection.com/en/universal/8-universal-stage-1a.html

How about this kit? Seems basic but able to do the job with the correct nozzle size

[Ben C34]

I just bought an aquamist kit. bit more expensive but as it injrcts based on injectors duty cycle it is easily tuned. The problen with boost referenced kits is 20psi at 3500rpn needs less flow than 16psi at 6500 rpm.

[Mr GTR-32]

Hi to all this has been a great thread i have read through alot of pages not all, i own a 340Rwkw R32 GTR with -9 garret turbos on 98 ron fuel with a PFC Ecu and all supporting mods blah blah blah.

Basically not to get of topic Im interested in running a WMI to see if i can get a little more grunt mid range grunt with more safe boost, as my turbos run out of puff on 18Psi up around 7200-7500rpm.

Can any kind member be able to recommend a reputable work shop in Sydney NSW that can install this kit for me as Im not interested in DIY rather pay for the peace of mind ive spent enough on my re build already dont need to risk another haha.

This has been such an interesting read and id rather like to try this than go the expensive route of E85 fuel.

cheers,

Dave

[discopotato03]

There is a degree of difficulty and expense going either way as in W/WMI or E70/85 .

With a bit of mucking around and a willingness to be accurate you can blend small amounts of ethanol into your 98 PULP and get reasonable results . This is the cheapest way to go about it but if there's a downside it's having to do it properly and consistently . By this I don't mean to within 1-2% either because if people are getting tunes wide enough to run E70-E85 , or even 66-90% , then you running within 5% of what you're tuned for eg splash blend E10-20 isn't going to be a biggie .

As I said all ways have risks , get bad tank of eth it's a risk . WMI pump failing under load - it's a risk . Get the splash blend wrong it's a risk .

Method of splash blend , work out how much E70 or preferably E85 gets your 98 PULP to the desired octane . Divide that litre number by 4 and plan to gass up in 1/4 tank increments . So , if you worked out say 10L of E85 does the trick get used to adding 2.5L per 1/4 tank . Doing it other ways often leads to ethanol percentage creep because it's difficult to work out from a fuel gauge exactly what volume is in your fuel tank . If you add a consistent blend then the percentage shouldn't change . Could even carry set volume containers so you can literally measure out how much E70/85 you're pouring in so you can't easily screw it up . In the above example a 2.5 and a 5L container covers it . It could have been a 5 and a 10 depending on what you tune for .

One tune no WMI or the need for real big fuel pumps and injectors . I believe having an enhanced performance car means being more attuned to its running characteristics so you know without being told when somethings not right , and nursing it until the problem is found and fixed . I don't need gauges to tell me if my round town tunes and or blends are out though a wideband is really handy .

Only you can know if saving time/effort or money is your priority .

Your call cheers A .