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Discussion Starter #1
There have been a few off and on conversationg about this topic on here and many other forums as well. I se a fair bit of confliction in everybodies understanding of W/M Injection, so I thought there sould be a thread to discuss some theory.


To begin, Id like to talk about Methanol concentration, and the post below, which was written by an intelligent engineer with a turbocharged Miata:
Recently, I'd noticed that my rate of consumption has been down quite a good deal. IOW, I haven't had to fill the tank for a while. Did a pressure-test on the system and found that the pump was operating normally, so I pulled the nozzle out of the inlet pipe to inspect it.

Now, we all know what a normal, healthy nozzle looks like on the inlet side, right?



Right, it's got a cute little filter screen, made of stainless steel, around the inlet to prevent foreign matter from clogging the delicate little hole in the end. Well, here's what mine looked like:



WTF, right? Where did the screen go? After a brief search, I found most of it at the bottom of the nozzle assembly, clogging the hole that it's supposed to be protecting:



Nice, eh?

This particular nozzle was purchased from one of the major kit vendors, and has been installed on the car for about a year and a half. I've been running about 1/3 methanol to distilled water, which is certainly not an excessive amount. And yet that little screen simply disintegrated. Can't imagine how long it would have lasted were I running 50% methanol, as is the case with the "boost fluid" sold by most of the WI kit companies as being compatible with their systems.

On the plus side, I hadn't re-mapped my ignition table since moving from CA to FL, and apparently that 93 octane gasoline is some pretty good stuff as I hadn't been getting any knock. On the minus side, this was the one failure more that my failsafe system couldn't detect, and of course, it's one that I never expected to happen.

Needless to say, I'm done with Meth. From now on, it's pure water. That, and apparently I need to advance my ignition a bit more. :D
 

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More than anything I'm interested in the last line. Pure water. No fooling around with meth, hadn't really thought about that before.
 

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what would the benefit of pure water to the fuel system accomplish? wouldnt it cause the plugs to burn out as h20 is not a flammable liquid or gas?
 

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Well in theory, pure water would simply reduce the temperature of the air that is coming in the combustion chamber. Thus eliminating possible predetonation and making a more efficient "bang".

Which would be great if you are running a smaller intercooler than you should or are really pushing the turbo on the top end of the efficiency range.

Thus running water injection vs none would let you run a little more psi than previously possible prior to getting detonation.
 

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Discussion Starter #6
The decrease in IAT is only part of it. Methanol is more volatile than water so it will lower IATs more effectively, but the water will actually improve knock resistance during the combustion process.
Methanol is high octane fuel so it will have added knock resistance but I'm pretty sure water does a better job.
 

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Classic Man
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The decrease in IAT is only part of it. Methanol is more volatile than water so it will lower IATs more effectively, but the water will actually improve knock resistance during the combustion process.
Methanol is high octane fuel so it will have added knock resistance but I'm pretty sure water does a better job.
true. the action of converting water droplets to vapor takes a LOT of energy, that energy will come from excessive heat in the combustion chamber. things will be much cooler and that SHOULD enable you to make some additional power.


member Jakers on here uses water injection in his auto x class since its not illegal. on his endyn supercharged wagon (rip)
 

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Discussion Starter #8
What I wonder is why we see these high concentrations, and even pure methanol injection.
I have a theory that some of these drag racers who are experimenting with W/M Injection are looking at IAT and making the connection that "more meth = lower IAT" but are not really sure what is best for preventing detonation.

I dont have the exact quote on hand, but I read an old (1930s) book hat discussed this, and the author basically said that 50%+ mixtures are not ideal and even that it could cause pre-ignition. Ill see if I can find the real quote though, in case Im mistaken.

I just have a hard time with conflicting information. Youve got an engineer saying one thing albeit about engines that are very old now, and youve got Joe racer saying the opposite but with the argument that they have personal experience.
 

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I just wanted to say that I meet a guy that had the same thing happen as above and when he contacted the company about it, they told him he should be running 50/50 water/meth (he had 60/40 for some reason), and that he should check all parts for wear and replace before that happens. I would like to see a test where some one uses different mixtures of water/meth and see which one actually helps prevent detonation the most, and makes the most power. I've seen some of the domestic guys running water/meth and they all had different combinations. One guy was running 75% water, 25% meth and said that was best.
 

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I guess it all depends on all of your variables. What fuel you are running, turbo size, intercooler size, timing, ect. I've always liked the idea of water injection because of it's cooling/cleaning properties. That, and it would be cheaper to run.
 

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I have the AEM Water meth kit on my STi. It works great but I might switch it the a Hydramist kit for the peace of mind because it has a much better fail safe.
I use 30/70 (30 water / 70 meth) By weight

BTW, there are 2 types of mixing water/meth.
1)By Volume
2) By molecular weight (more exact)

ie. Let's say you have 4 gallons total. 3 Meth gallons and 1 gal. of water
When you mix them you'll have a volume ratio of 25/75. However, since meth is less dense than water you'll have a weight ratio of 30/70.
And the total volume of the 4 gallons mixed would be 3.857 Actual gallons.

Same goes if you mix 1gal Water / 1gal Meth
►By Volume = 50/50
►By weight = 56/44
►Actual gallons = 1.929

I have an MS Excel program that lets you calculate gallons, percentage, add gallons etc...
It's called "bcbluesmethanolmixingToolKit"
 

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I have the AEM Water meth kit on my STi. It works great but I might switch it the a Hydramist kit for the peace of mind because it has a much better fail safe.
I use 30/70 (30 water / 70 meth) By weight

BTW, there are 2 types of mixing water/meth.
1)By Volume
2) By molecular weight (more exact)

ie. Let's say you have 4 gallons total. 3 Meth gallons and 1 gal. of water
When you mix them you'll have a volume ratio of 25/75. However, since meth is less dense than water you'll have a weight ratio of 30/70.
And the total volume of the 4 gallons mixed would be 3.857 Actual gallons.

Same goes if you mix 1gal Water / 1gal Meth
►By Volume = 50/50
►By weight = 56/44
►Actual gallons = 1.929

I have an MS Excel program that lets you calculate gallons, percentage, add gallons etc...
It's called "bcbluesmethanolmixingToolKit"
this is a great post imo! very informative and perfect for this thread.
i have no intensions on running meth injection but im glad i glanced at this thread cause there is some great info in here.
 

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not just lower IAT and cleaner combustion but better FE for any given level of power. conventionally, cylinder temps are kept under control by fueling rich and using the excess fuel as an evaporative coolant. if you substitute 11:1 AFR, with 15:1 AFR and water as necessary for evaporative cooling, you get the same level of performance for lesser fuel, lower cylinder temps, lesser preignition and lower EGTs which will also mean that you can run lean without spewing out NOx.

I plan to implement microcontroller based water injection in a couple of months. should be interesting to see how that goes. a friend of mine had done a crude vacuum based setup in an 800 cc engine and he reported an FE increase from 40 mpg to 55 mpg with slightly better performance over stock. however, he found some water collecting in the oil pan and got rid of the setup. Im pretty sure that with tight control, one can get *all* the water to vaporize and not find its way into the oil.
 

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Meat Popsicle
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Seen those exact pics and this same topic covered before. Water is a great anti-detonation solution...methanol is not nearly as important in the equation. I'm sure Pat will chime in on this soon.

Run just enough alcohol in your mixture to deter mold from forming and call it a day. Methanol is a corrosive but high quality metals like stainless steel and carbon steel are nearly unaffected by it's corrosive properties. Metals that are composed of copper or zinc are more prone to corrosion...no telling what that screen was made of.

Maybe it's just me...but those pics aren't even close to being the same nozzle/inlet. Notice that the first pic shows the inlet hole being spaced far higher up compared to the 2nd pic with no screen. Not the same nozzles/inlets. No way to verify what type of metal was used for either screen.
 

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I see this kind of set-up on turbo drag cars a lot, but could you use it for high CR's on an N/A car?
 

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Meat Popsicle
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I see this kind of set-up on turbo drag cars a lot, but could you use it for high CR's on an N/A car?
Sure. The problem is that nearly every single kit that's produced relies on boost pressure as the activation point for the amount of mixture being injected. I have yet to see a kit that uses a controller that will begin injecting at atmospheric pressure. Usually the low point is like 2-3 PSI. A progressive RPM switch for NA setups would be far more effective since the manifold pressure would stay consistent across the entire RPM range at WOT.
 

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most definitely! if it is good enough for the high dynamic compression of in turbos, NA should be a walk in the park.
That's pretty cool if you can, it would def put the reliability of high compression back on track if people have a DD w/ high comp.

Sure. The problem is that nearly every single kit that's produced relies on boost pressure as the activation point for the amount of mixture being injected. I have yet to see a kit that uses a controller that will begin injecting at atmospheric pressure. Usually the low point is like 2-3 PSI. A progressive RPM switch for NA setups would be far more effective since the manifold pressure would stay consistent across the entire RPM range at WOT.
ah, that's why it's always marketed towards the turbo target markets, gotcha. I wonder if you could modify an existing WM kit to do this? I'd hope it would hold up better than those pics up top if it was developed too.
 

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I have said a fair bit about this previously on several occasions. Once was when a then site sponsor, Red Devil put out a promotional post with quite a few technical errors about wheres whys and hows and a few overstatements about results and understatements about problems. I copped some flack from a few members here at the time for criticising a sponsor.

Funny enough though, one of my statements was that methanol is quite corrosive, especially when mixed with a little water and that was strongly disputed at the time by Red Devil.

I said lets wait a couple of years and you will see or words to that effect, well that was a couple of years ago. I was using water injection before most of you guys where born so I already had some history.

A huge resource for water injection knowledge is the National Advisory Committee for Aeronautics (NACA) archive. NACA was the precursor of NASA and the archive is incorporated into the NASA site.

Most of the work was done during WW11 in order to give a short term power boost in combat with boosted piston engines. Fighters use it for emergency power in dog fights and bombers to boost power during take off so they could carry a heavier payload.

During war time, huge resources are devoted to getting a competitive edge and now we can access the reports.

There is a trick to finding them. They call it "internal cooling" NOT methanol injection or meth injection or even water/meth injection.

I found some mixed in with a lot of other reports about water or water/methanol injection into turbines so it takes a bit of sifting.

So far I found and downloaded the following. They are on piston engine performance, fuels and anti knock additive in general but contain a fair bit about water injection but there where still a lot more. Shoot me, I ran out of time one night and haven't got back there yet.:-

Here is the URL for the list of 48 reports I was searching.

NASA Technical Reports Server - NACA investigation of fuel performance in piston-type engines

Here are the copy and pastes of the title pages reports I downloaded so far.

TECHNICAL NOTES
NATIONAL ADVISORY COMMITTEE FOR AERONAUTICAL RESEARCH
No 211
AIRCRAFT ENGINE DESIGN.
By E. E. Wilson
Bureau of Aeronautics, Navy Department
January, 1925




NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS
TECHNICAL NOTE 2127
AN INVESTIGATION OF THE EFFECT OF TETRAETHYL LEAD AND
ETHYL NITRITE ON THE AUTOIGNITION CHARACTERISTICS
OF ISOOCTANE AND TRIPTANE
By J. U. Jovellanos, E. S. Taylor
C. F. Taylor, and W. A. Leary
Massachusetts Institute of Technology
Washington
June 1950




NATIONAL ADVISORY C0MMITTEE FOR AERONAUTICS,
TECHNICAL NOTE 3276
PROPERTIES OF AIRCRAFT FUELS
By Henry C. Barnett and Robert R. Hibbard
Lewis Flight Propulsion Laboratory
Cleveland, Ohio
Washington
August 1956




NACA
RESEARCH MEMORANDUM
A COMPILATION OF SUMMARIES FROM NACA REPORTS ON
FUELS RESEARCH, 1945-1952
By J. T. DiPiazza
NATIONAL ADVISORY COMMITTEE
FOR AERONAUTICS
WASHtNGTON
August 5, 1953




REPORT 1300
BASIC CONSIDERATIONS IN THE COMBUSTION
OF HYDROCARBON FUELS WITH AIR
By PROPULSION CHEMISTRY DIVISION
Lewis Flight Propulsion Laboratory
Cleveland, Ohio
Edited by Henry C. Barnett and Robert R. Hibbard




REPORT No. 232
FUELS FOR HIGH-COMPRESSION ENGINES
By STANWOOD W. SPARROW
Bureau of Standards




REPORT 1926
NACA INVESTIGATION OF FUEL PERFORMANCE
IN PISTON-TYPE ENGINES
By HENRY C. BARNETT




WARTIME REPORT
ORIGINALLY ISSUED
August 1944 as
Advance Restricted Report E4H15
CONTINUOUS USE OF INTERNAL COOLING TO SUPPRESS KNOCK
IN AIRCRAFT ENGINES CRUISING AT HIGH POWER
By Arthur H. Bell
Aircraft Engine Research Laboratory
Cleveland, Ohio
NACA
WASHINGTON




WARTIME REPORT
ORIGINALLY ISSUED
August 1944 as
Advance Restricted Report [email protected]
SOME EFFECTS OF INTERNAL COOLANTS ON KNOCK-LIMITED AND
TEMPERATURE-LIMITED POWER AS DETERMINED IN A
SINGLE-CYLINDER AIRCRAFT TEST ENGINE
By Jerrold D. Wear, Louis F. Held, and James W. Slough
Aircraft Engine Research Laboratory
Cleveland, Ohio
NACA




TECHNICAL MEMORANDUMS
NATIONAL ADVISORY COMMITTEE FOR AERONAUTICAL RESEARCH
No 873
EXPERIMENTAL STUDY QF IGNITION BY HOT SPOT
IN INTERNAL COMBUSTION EGINES
Publlcations Scientiftques et Techniques
du Mlnistere de L'Alr
No. 115, 1937
Washington
August 1938
 
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