Why it's WATER injection

What WATER (not alcohol) injection does
There are two reasons blower cars tend to detonate. One is high inlet air temps, the other is higher cylinder pressure (which in turn further heats the charge). There are a couple of ways to deal with this. One is higher octane fuel, which is not practical for day to day use given what is available at the pump. Another is making the AF ratio very rich, which is used by all blower tuners. The extra fuel acts to cool the intake charge. This costs power, but not to a great degree. Another way is to retard timing under boost. This is also used by nearly all tuners. Timing retard also costs hp and has somewhat limited effectiveness at preventing detonation. Lowering engine temp by better cooling helps, to a small degree. Lowering CR is quite effective. Based on both theory and practice, if you have the choice between lower CR and more boost, or a higher CR and less boost the former will unequivocally produce more hp. The explanation is somewhat long winded and I don't have time to go into it now. The only downside is decreased fuel efficiency under light load (where a street auto engine spends 95% of its' time).

Lowering intake air temps can markedly decrease detonation. This is done by the use of intercooling. The resistance to flow through the intercooler will decrease apparent blower efficiency and hence cost power, but this is more than compensated for by the denser intake charge (due to cooler IAT) and the ability to run more boost without detonation. As noted above, extra fuel also cools charge temperatures. Methanol is a fuel. It has a much higher heat of vaporization than gasoline. So, using methanol instead of gasoline as the "extra" fuel is more effective than using extra gasoline. Methanol also has an octane rating of ~99, so it will raise the octane of the charge in amount proportional to the quantity compared to gas. Just like mixing a little race fuel with the pump gas.

This brings us to water. Water has an even higher heat of vaporization than methanol. It is not a fuel and has no "octane" at all. It cools better than methanol due to the higher heat of vaporization. It also slows the combustion process after ignition, this dramatically reduces detonation and is primarily why the most effective injection fluid is at least 50% water. Why not all water? Well, that does work. So does straight methanol, but not as effectively. What practice has shown is that a 1:1-2:1 water:methanol mix works best. I don't know the theoretical explanation for this. I suspect it has to do with water displacing air. Of course, methanol does too but it allows less gas to be used which will partially compensate. Water increases the need for a strong spark because it is so effective at slowing combustion. That's one limiting factor in it's effectiveness and maybe why some people report better results with methanol. BTW, the combustion slowing effect will require some of timing we already took out to be added back in.

So, max hp for a given octane fuel is obtained by lower CR, higher boost, water/methanol injection, intercooling, careful tuning, and a strong spark.

Cliff's Notes: If I hear "alky injection" one more time I am going to scream. Call it WATER injection or go home.

Rich

cool stuff...but curious, whats wrong with the term alky injection? isnt that short for alcohol (methanol) injection?

Semantics. ;)

'Cause it's the water that's the more important component of the injection fluid.

Rich

alky or meth just sounds cool. lol

You guys are doing this just to mess with me, right?

Rich

I get people all the time telling me that I can't drive my car in the rain.......when I say I have been through many downpours with it and it runs just fine (technically better) in the rain they act like I am full of crap :shrug:

You guys are doing this just to mess with me, right?

Rich

Totally. :D Although, the word usage has never really bothered me.. even though i run a 90% water mixture in my car, i still end up calling it meth injection in casual conversation alot.

I disagree on the importance of water,

Methanol has a lower heat of vaporization, and it has a lower thermal conductivity constant (usually denoted k) but there is more going on than just that.

Methanol has a kick ass flame travel speed especially in a rich environment. The flame travel speeds even at stoich are better than gasoline by far which is nice because you do more positive work when more of your mixture burns at TDC. On top of that it is making use of space by adding heat while still offering a better cooling effect than gasoline. Anyway I'm rambling.


Water
Advantages

Higher heat of vaporization (pulls more heat out of intake)

Disadvantages

Higher specific heat. As water passes thru the combustion process it carries heat with it. That is heat that could be doing work.

Makes for dead space in combustion

Slows flame travel speed. More ignition advance is needed for both flame propagation AND flame degree. More of the mixture is started BTDC in order to balance as much mixture burning right ATDC so your doing more negative work. On top of that mixture is not burned as close to TDC where change in volume is happening fast relative to crank angle.


Methanol
Advantages

Carries a good heating value

Superior flame travel speed. Even better than gasoline

3 or 4 times higher heat of vaporization rate

Adds to total heat addition to the process, instead of taking from it

Its heat of formation of the products is less than that of what pure excess water's specific heat



Disadvantages

Hard on parts?


I think pure methanol is much better than a mixture of water and methanol. I think this is also the common idea with the Buick guys who depend on alcohol injection. I think most injection manufacturers tell people to use a mix just so the fluid isn't so hard on the parts and pump.

I from personal experience have not had any issue at all seeing a gain with methanol injection. I have NEVER seen a gain with pure water injection. I've seen very mixed results with mixes of water and methanol. Usually after adding lots of timing we usually get back to where we started with most mixes. The extra timing is coming from the slower flame travel speeds!

My idea for an ideal kit is to use as much methanol as possible without damaging parts. Then, replace gasoline with as much methanol as possible.. So that means pull back on your fuel and add an appropriate amount of methanol.

Remember that methanol’s lower heating value is a good bit less than gasoline but the catch is you burn much more of it per lb of air so its total heat addition is actually higher than gasoline.


Also remeber that the higher heat of vaporization of water might sound attractive to pull heat out of the intake, but seeing how the water passes thru the combustion unchanged and it has a high specific heat it also carries ALOT of heat out of the combustion process. Heat that could otherwize be doing expansion work!!!

not to mention that again, its dead space.

Also.. the increase from power can only come from a car thats running really rich, since water displaces fuel leaning out the mixture. But the amount of alcohol, and its relation to fuel used.. play a major role in creating power with straight alcohol.

Straight (alcohol)methanol will always yield more power. As a matter of fact, you'll make power without changes injecting methanol, unlike water that requires something else to change for power to occur. This statement is a proven.


Taken from Razor, owner of alkycontrol.com http://www.turbobuick.com/forums/alcohol-nitrous-propane-tech/157291-50-meth-50-water-21hp.html?highlight=mixture

I should use quotes, but I'm lazy tonite and mean no disrespect.

The heat carried out of the exhaust by the water is the heat we removed from the intake charge, this is the whole point afterall and why water is an excellent choice.

Methanol can actually induce detonation when used in this application in mixtures over 50%.

Injecting water is not going to displace fuel and lean the mixture. The fueling strategy knows nothing about the water injection and the same volume of fuel will be injected at the port. Water does not participate in the combustion process, but it does massively expand when turned to steam which contributes to in-cylinder pressure.

Hit the head of a piston at TDC with a hammer (in your imagination) and tell us what happens. The crank isn't going to rotate, the rod is inline with the crank throw. TDC is not where you want max pressure to occur.

There are numerous studies on water/anti-detonate fluid injection done with aircraft engines. Much of the serious work was carried out for the presecessor of NASA which places the info in the public domain and available. If water injection is effective for 1000+ hp force inducted aircraft it will be effective in our engines as well.

Effect of engine-operating variables and internal coolants on spark-advance requirements of a liquid-cooled cylinder

http://hdl.handle.net/2060/19930093147

above is a link to the pdf. This is not going to be for everybody, but if you're willing to study it there will be information that applies to us.

http://ntrs.nasa.gov/search.jsp?No=0&Ntt=detonation&Ntk=all&Ntx=mode%20matchall&N=0

edit: added a search link on DETONATION for the NASA / NACA archives.

The heat carried out of the exhaust by the water is the heat we removed from the intake charge, this is the whole point afterall and why water is an excellent choice.

Right, its that plus what it soaked up during combustion. Do you think you can throw a penny in a fire and pull it later at the temperature you threw it in at?

Methanol can actually induce detonation when used in this application in mixtures over 50%.

Wheres your source on that? I can see how this may be possible, but it would be a stretch and a half, and if I don't see it happening easier than using gasoline alone. methonol has more induction time and at a higher temp than gasoline.

Injecting water is not going to displace fuel and lean the mixture. The fueling strategy knows nothing about the water injection and the same volume of fuel will be injected at the port. Water does not participate in the combustion process, but it does massively expand when turned to steam which contributes to in-cylinder pressure.


I don't know why I quoted razor on that. I'm guessing he ment to say that they (tuned) leaned out the mixture on the spray.. who knows.


Hit the head of a piston at TDC with a hammer (in your imagination) and tell us what happens. The crank isn't going to rotate, the rod is inline with the crank throw. TDC is not where you want max pressure to occur.

No where did I infer that it would happen instantanously. I said you need as much of it to happen at/near TDC as possible. If you'd like I can explain why.



There are numerous studies on water/anti-detonate fluid injection done with aircraft engines. Much of the serious work was carried out for the presecessor of NASA which places the info in the public domain and available. If water injection is effective for 1000+ hp force inducted aircraft it will be effective in our engines as well.

The study you cite (written in the 1940's) show a power gain when there is a condition of abnormal combustion. So what they are saying is there is X% to be had with water injection IF your having a problem with knock. The study is geared more for reducing rich mixtures needed for knock sensitivity by adding water, especially for the benifit of reducing isfc especially in cruise.

Actually if you read the entire text there is power to be gained by increasing the charge density with water injection assuming the injection point is not right at the port, regardless of knock limitations.

For a given volume of water/coolant injection there is a finite amount of heat/energy that it will absorb and remove from the cylinder.

I am looking for print studies on methanol induced detonation as it pertains to our use. I will post the link(s) when I have it for your consideration.

I agree with Mark that straight methanol is the worst of the choices along the alcohol---water continuum.

Rich

Water displaces fuel. Easy.

Methanol is a fuel.. of very high octane.

Which can make more power.. easy.. which one burns.

Thousands of dyno pulls... tell the story.

Whether someone chooses to believe.. thats a whole other story. Without data.. real world.. its all smoke and mirrors.

Alvin.. you are correct.

Anyone need dyno sheets before and after? How bout datalogs on a faster car?

See when data is available, the rest becomes hog wash :D

Actually if you read the entire text there is power to be gained by increasing the charge density with water injection assuming the injection point is not right at the port, regardless of knock limitations.


There is also power to be lost, Your displacing usable space.


For a given volume of water/coolant injection there is a finite amount of heat/energy that it will absorb and remove from the cylinder.


NO there is not, not the way youmean it. You put water thru a combustion process and YOU WILL take heat out of the combustion process.

http://www.turbobuick.com/forums/alcohol-nitrous-propane-tech/201570-fast-alky-logs-without.html

Data :bow:

Mo data

http://videos.streetfire.net/video/4bae3760-bfe8-47c0-bf74-989201817f00.htm

Same car a little faster. No water was used. ;)

No one is saying methanol won't work. They are saying it's less effective than a water:methanol mixture.

Rich

There is also power to be lost, Your displacing usable space.



NO there is not, not the way youmean it. You put water thru a combustion process and YOU WILL take heat out of the combustion process.

Sure, water cools the charge. That's one of the mechanisms by which it works :confused: But, of course, it still makes more hp if the additional boost that can be used is applied.

Rich

This thread is like saying McDonalds hamburgers are the best tasting hamburgers you can buy. See anyone not ever tasted a burger will argue its meat, bread, cheese, etc.. all the same as the Applebees Filet burger.

When you start running high boost, high timing, start to squeeze every last ounce of available power from a combination.. that is when the experience is gain. Until then its all internet bench racing "Car should run an easy 9 second pass".. nothing easy about it.

I have tuned way too many cars to develop my position in my statement more power will be made with 100% straight racing alcohol injection over any mix thereof. Maybe its what works for me.. but it does for way too many racers.

If your car doesnt detonate, or slightly detonates.. water injection will stop the detonation. And will bring power down as well. If the detonation is severe... water will not stop it like alcohol can.

On a turbo buick, you can get 15-16 PSI typical on pump gas 93 octane. Add water injection.. same engine with tuning we can get 19-20 PSI boost.. add mix 50/50 same engine can now be taken to 24-25 PSI before "Knock" starts showing on the scantool. Same engine now we utilize 100% methanol on top of the pump gas it can taken 30+ PSI without a trace of "knock". Been done 100's of time, same experiment, different cars.. same result.

See if the goal was 20 PSI..or 24 PSI.. water/mix would get the job done. Once the timing and boost goes up past that.. fugedaboutit.

Whether you choose to believe this or not.. thats optional. Can lead a horse to water, cant make it drink :D

What i'm trying to say is that if your motor can run 30 PSI on C16.. it can run 30 PSI on 93 octane pump gas and methanol injection.

The Buick from factory has a small IC. Without an IC, typical limits are 20 PSI. Every lb of boost =11 degree's. 20 x11=220 + ambient(80)=300 degree's. With alcohol injection, that temp can be brought down to ~150 DF.

So 15 PSI boost also depends on what timing is being run. Big difference between 14 degree's and 24 degree's. On pump gas the norm is to drop timing hard. But this raises exhuast gas temps hard too. So running 14 degree's timing has its share of consquences. Higher the timing, the less EGT.. but makes the engine prone to detonating. Here if you have octane, you crank the timing.. egt's come down.. motor is happier making more power.

Tuning allows to maximize your particular setup, and make decisons whats the next step. Guessing is bad, and always leads to avoidable broken parts. Data aquisition is the new thing for keeping an eye on things happening. Pay attentions and give your engine what it tells you it likes.. the rest is simple.

That knock sensor tells a story in itself.. if it doesnt knock.. you'll be able to stretch parts out to unbelieveable levele.

My car has run 132+ in the 1/4 weighing with driver 3800 lbs. Its 6 cylinders, cast pistons, cast crank, 2 bolt main block, even OEM rings.. on 93 octane plus methanol injection. This months GM HiTech in the recap from the Nationals in BG is a picture of it with the front tires up. It ran 10.57 and 132.7 with a filled to the rim tank of 93 per the class it competed in. Won the class, fastest ET, fastest MPH, most consistant.

This water arguement i've been reading about it for years.. after a thousand+ dyno pulls.. you start giving up on the issues with water and tuning thereof.

HTH

Methanol
RON 106
MON 92

C16
MON 117
RON ???

C16 has a much higher MON than methanol. But methanol has a much higher (~4X) the heat of vaporization of gasoline. That is why it is such an attractive fuel for a blower car - it can eliminate the need for an intercooler. The other reason is that the eenrgy content of methanol of an optimal methanol:air mixture is ~10% greater than for gas.

You would be better off running a blower car with straight methanol than with race gas. So, if you add enough methanol to your mixture, I guess you could approach this. Is this what Julio is doing? What would happen with a methanol/water mixture as the primary fuel? Would it allow even higher boost???

Rich

To add to the above, very aggressive blown methanol fueled drag cars waste 25% of the delivered fuel out the exhaust.

Julio - Do not assume the people you're conversing with are inexperienced. And I would love for you to share some datalogs with us, hopefully not just OBDII data rate stuff but data from Innovate or another solution that has a reasonable rate. Thanks in advance for sharing.

This is very interesting stuff. On humid days airplane engines make alot less horsepower. This is documented in airplane manuals and engine tests. This would lead me to believe that water does not help power output. Cold dry air is the most conducive to making power.:)

This is very interesting stuff. On humid days airplane engines make alot less horsepower. This is documented in airplane manuals and engine tests. This would lead me to believe that water does not help power output. Cold dry air is the most conducive to making power.:)


There's no question that IF you could run the same amount of boost with the same IAT's with and w/o water, you'd be better off without it. That's what your (correct) observation speaks to as much as anything else.

Rich

Octane rating is flawed on methanol. Most of the race fuel sites list in in terms of "purity" not octane. It would be impossible for a top alcohol dragster to make that power on 106 octane.

For every ounce of fuel you have to double it in methanol. Takes twice the amount of alcohol as it does fuel to generate the same power. Its a little less, but in laymans terms.. typically rite on.

If I reduce my injectors by 20%, now I have to introduce twice that amount in methanol. This high volume is where the majic is. This is what allows the higher boost due to the amount being pumped it.

If you look at commercially available water injections systems, they have nozzles that flow very small amounts. Perfect example.. Aquamist. Their M1 nozzle is like 1 GPH and their pump runs max 80 PSI. Anything past 5 GPH and you start getting into bogging. On a mid size engine.

I run 25 GPH at 150-170 PSI methanol.

Let you do the math. Inject this amount with any water concentration.. you'll blow any flame the motor has rite out.

The datalogs were done using FAST. Typical race car computer.

Make your system 100% alcohol compatible.. go get your data. Its not on paper.. but in real life. 100% compatible allows to run from water to alcohol.. anywhere in between.

Point being missed by this thread is volume being injected.

Why not just run it on methanol? I have no idea what you are talking about wrt purity of methanol? You are saying impure methanol is more detonation resistant than the 99.85% pure stuff we use in racing? We run an alcohol Hemi and it sure does detonate. It also makes power. It also gets rebuilt frequently. We buy pistons "by the case"! A street motor would never last under the conditions a blown alcohol race motor runs under, so I am not sure of the point you are making. My own race car is also methanol fueled, so I do know a bit about it.

Rich

The problem with running methanol full time is servicing, washdown, fuel system, etc.

Bring out the crayon..
METHANOL

M1™
M1 Racing Methanol has a 99.95% minimum purity - the highest purity available in the U.S. With M1, engines run cooler and are less subject to corrosion. VP uses only lined drums which prohibit rust, corrosion and metal deposits that can contaminate fuel delivery systems. Recommended for all methanol-legal racing applications.

where does it talk about octane?

mgray.. yes.. but only under very high demands. Not full time. Easy ;) A lot easier with the systems available. KISS is the best principle. Complicate your self as needed. Careful with "placing the carriage before the horse" :D Which seems common in this thread.

I have FAST software and you offered up data. Where can I download the logs? PM me for my email address if you can't ftp. I'll assume that knock retard is turned on and logged via GM knock module.

I run 25 GPH at 150-170 PSI methanol.

Let you do the math. Inject this amount with any water concentration.. you'll blow any flame the motor has rite out.



Ya okay, so I did the math.

methanol sg - .795
gallon water 8.33 lb/gal
gallon methanol 8.33 * .795 = 6.62 lb/gal

25 gph = 165.56 lb/hr

bsfc blown methanol 1.1

165.56 / 1.1 = 150.51 hp supported

So using your example of raising the boost another 15+ psi with your straight methanol at 25 gph are you saying you're only getting 10hp per psi? If so you've got a problem. If you're just throwing crap together for the post then you have a problem. No data logs, no IAT data, no dyno data but yet just a link in your sig to "alkycontrol".

I posted the link to a single test done for the government with dozens of other tests in the search link. There is excellent info there because detonation limited engine performance was a serious national security issue when our aircraft were powered by pistons. The government spent millions researching detonation and ways to extend the performance of aircraft. I read the other thread where today's popular "tuners" were claimed to run 100% methanol. I don't care what its claimed they run. We're here to discuss the technical merits and pitfalls of various parts and solid research and performance data allows an individual to come up with their own conclusions.

Please again, post up some data, not marketing material, heresay or Corvette tuner stuff lol.

I'm not trying to be a 400lb gorilla but I want hard data of why water isn't the necessary ingredient suppressing detonation in water injection.

So using your example of raising the boost another 15+ psi with your straight methanol at 25 gph are you saying you're only getting 10hp per psi? If so you've got a problem. If you're just throwing crap together for the post then you have a problem. No data logs, no IAT data, no dyno data but yet just a link in your sig to "alkycontrol".

First, Julio races turbo Buicks last time I checked. The little 231 v6 with 160 cfm heads doesn't pick up the 20 - 25 hp/psi that LS1 folks are used to.

Second, I have plenty of logs of my own Methanol runs. I opened one random log file where I was running 24 psi boost (26 peak) in the dead heat of a South Louisiana summer. IAT was running at 103 deg F. I hit the gas and it started to rise up to 105 deg F, then the Methanol came on and cooled it all the way down to 86 deg F, then it rose back up to 90 deg F by the end of the run. That's right, 26 psi boost and 16 deg below ambient temperature. The knock retard spiked when I first hit the gas (like it always does), then fell back to zero and stayed there. The interesting thing was that the IAT fell all the way to 72 deg after I let off since the residual Methanol was evaporating and the air was no longer being heated by the turbo.

Mike

Yes I was able to comprehend he was referring to a Buick v-6. I didn't realize he was running 30+ psi on a stock engine without preparation. Truly remarkable and a testament to his ability.

IAT below ambient is fairly normal and repeatable when fuel is vaporized in the intake stream/plenum such as with a blow through carb or water/methanol injection. I suppose that's why it used. Who woulda thought.

Sure, water cools the charge. That's one of the mechanisms by which it works :confused: But, of course, it still makes more hp if the additional boost that can be used is applied.
Rich

That is like handicapping yourself so that you can run more boost. We are trying to tell you there are better ways of doing this.



I think the point is to take heat out so you can add more fuel and air, and adjust the AFR and timing accordingly (i.e. not simply throw water in there to cool a combustion chamber that doesn't need cooling. :shrug:).

Right, the point is you can take heat out so you can add more fuel and air. BUT by throwing water in the process to take heat out you are taking heat out of combustion.. pure and simple, no way around it. Why not cool your intake, boost flame travel speed, AND add work to your cycle! By using water you are throwing work out the tail pipe in the form of superheated vapor.



To add to the above, very aggressive blown methanol fueled drag cars waste 25% of the delivered fuel out the exhaust.

Wow you don’t say. :) A moderately conservative blower tune with 93 octane does the exact same thing. 14.7/11.5 = 27% fuel that goes right out the tail pipe..


Julio - Do not assume the people you're conversing with are inexperienced. And I would love for you to share some datalogs with us, hopefully not just OBDII data rate stuff but data from Innovate or another solution that has a reasonable rate. Thanks in advance for sharing.

Likewise.. I’ve had a few cars on the dyno :)


This is very interesting stuff. On humid days airplane engines make alot less horsepower. This is documented in airplane manuals and engine tests. This would lead me to believe that water does not help power output. Cold dry air is the most conducive to making power.:)

Yep, on a humid day you need more air (humid) than in a dry case to have a stoich burn. This is easy to play with by doing a chemical balance on humid air and the fuel of your choice.. Remember the moles of water go thru the combustion process and with it take heat. Same exact reason why for POWER 100% straight methanol is a better choice than some mix of water and methanol



IAT below ambient is fairly normal and repeatable when fuel is vaporized in the intake stream/plenum such as with a blow through carb or water/methanol injection. I suppose that's why it used. Who woulda thought.

New one for me! I’m going to try to build a engine that burns only fuel in liquid state. Seriously, who are you trying to fool. Any fuel used by the engine has to vaporize first.



Methanol has some serous advantages. It adds heat (work) to the cycle only after removing it from the intake charge first. It does not remove heat from the combustion process. It vaporizes quickly and with a higher specific heat, so it does a good job pulling temperatures down. Its adiabatic flame temp is LOWER than gasoline which makes it nice for capping detonation. Its induction period and AIT is also such that its harder to detonate wtih. Its flame travel speed is HIGHER than gasoline. And its flame travel speed is much much higher than a cycle involving water.


Flame travel speed is serous business when talking about the efficiency of an engine.

New one for me! I’m going to try to build a engine that burns only fuel in liquid state. Seriously, who are you trying to fool. Any fuel used by the engine has to vaporize first.





Any fuel in excess of stoich is wasted from an energy standpoint and is used to cool the cylinder or intake charge in an effort to combat detonation and pre-ignition and allow for the desired tuneup. Running an engine rich on methanol as an enrichment fuel does not make extra power from burning methanol, oxygen is required to burn the fuel and as its richer than stoich there isn't any oxygen left for the burn. The engine doesn't pick and choose whether to burn gasoline or methanol. Rich is rich. Heat removed from vaporization increases air density and cools the combustion space and end gases. That heat is lost out the exhaust where the energy is dissipated and placed back into the atmosphere. Methanol absorbs more heat than gasoline and as an enrichment fuel only that is its only contribution.

For this pupose water is an excellent coolant.

I should also add that power increases seen from a wategate controlled turbo system may be more dramatic than with a supercharger as the cooler, higher density charge will also drop in pressure for which the turbocharger compensates for by increasing the mass flow through the system allowing more fuel to be burned. This is assuming a progressive water injection strategy.

I think we are talking past each other now. The M group is saying that methanol is a superior "boost fluid" to water. The W group is saying the opposite. Both may be right because the main M proponent is talking about small V6's with inadequate (?iron) heads running a turbo to produce 30lbs of boost and the W group is primarily referring to street/strip V8's using unleaded pump gas, with centrifugal blowers and much lower boost and with a knock retard system. Also Julio is using very large amounts of methanol. I wonder what his results would be if he just mixed up some "M20" and ditched the "alkycontrol" system? I wonder if he did that and used his system to inject water? Could he raise the boost even more? Could he make even more power?

No one here knows everything, there are a lot of experiments left to try. But the best rigorous data available suggest that water is the best practical antidetonation fluid for a supercharged motor.

I think we are going to have to agee to disagree on this one. I do have a question for Julio: what gasoline are you using? Pump unleaded? That may be another difference between the models we are using.

Rich

I have FAST software and you offered up data. Where can I download the logs? PM me for my email address if you can't ftp. I'll assume that knock retard is turned on and logged via GM knock module.

Email me at idoxlr8_70@yahoo.com I can send you .logs. Let me know if you have the "old" c-com or new XFI..Most of the new data is on the XFI.

This is a recent thread on TB.com
http://www.turbobuick.com/forums/alcohol-nitrous-propane-tech/201570-fast-alky-logs-without.html

Should be pretty simple on an untuned car :) One run was at 8 PM, the other was the next morning. Outside air was a little cooler on the night run, but non-the less.. you can see injector duty cycle come down with the methanol as well as intake air temp.

HTH

First, Julio races turbo Buicks last time I checked. The little 231 v6 with 160 cfm heads doesn't pick up the 20 - 25 hp/psi that LS1 folks are used to.

Second, I have plenty of logs of my own Methanol runs. I opened one random log file where I was running 24 psi boost (26 peak) in the dead heat of a South Louisiana summer. IAT was running at 103 deg F. I hit the gas and it started to rise up to 105 deg F, then the Methanol came on and cooled it all the way down to 86 deg F, then it rose back up to 90 deg F by the end of the run. That's right, 26 psi boost and 16 deg below ambient temperature. The knock retard spiked when I first hit the gas (like it always does), then fell back to zero and stayed there. The interesting thing was that the IAT fell all the way to 72 deg after I let off since the residual Methanol was evaporating and the air was no longer being heated by the turbo.

Mike

Mike, your right on :bow:

I think we are talking past each other now. The M group is saying that methanol is a superior "boost fluid" to water. The W group is saying the opposite. Both may be right because the main M proponent is talking about small V6's with inadequate (?iron) heads running a turbo to produce 30lbs of boost and the W group is primarily referring to street/strip V8's using unleaded pump gas, with centrifugal blowers and much lower boost and with a knock retard system. Also Julio is using very large amounts of methanol. I wonder what his results would be if he just mixed up some "M20" and ditched the "alkycontrol" system? I wonder if he did that and used his system to inject water? Could he raise the boost even more? Could he make even more power?

No one here knows everything, there are a lot of experiments left to try. But the best rigorous data available suggest that water is the best practical antidetonation fluid for a supercharged motor.

I think we are going to have to agee to disagree on this one. I do have a question for Julio: what gasoline are you using? Pump unleaded? That may be another difference between the models we are using.

Rich


Rich, this thread has moved nicely :bow: . I have tried mixing water in, and everytime.. the same result was a loss in MPH. Pretty much all of my data I personally do on a 1/4 mile track. I dont like dyno's becuase of the time the motor is on the roller.. unlike a track surface I can go through way more time at WOT. My IAT's are slammed to ambient or a few wdegree's above on my own car. Case in point, I will see on an 80 degree day ~190 IAT at 26 PSI without the injection, with its at ambient ~80-85 df. My nose on the car is not condusive to a FM IC, unlike some of my Buick friends that run BIG FM's on their cars.. they will see approx 30-35 DF increase over ambient whereas I see 100+DF.

Fuel I use is standard 93 octane unleaded, and I try and keep the same gas station.. flavor of the month is BP93. At BG I ran Chevron93.

Not saying I know it all, I feel fortunate to be involved with a lot of shops doing tuning on LS1's and the results thereof. 3.5 years in business fulltime.. 5 years using injection.. I get some notches on my belt. And develop my biases from feedback recieved from tuners on the subject.

I understand the argueement of water as it works, have read the papers, and understand how it works. In a practical sense, every tuner I know off that has tuned on both mediums.. will prefer straight. It is way more forgiving to tuning mistakes. Less time on the rollers $$, less issues with outside temp changes in the tuning.. the cooler it gets outside, the more issues there are with water.. meaning customers are happy, tuneup stays stable, detonation is kept in control, win win scenario.

Are there scenario's I feel 50/50 is better. Absolutely. Perfect example are engines that cannot be tuned. meaning no ability to make changes to fuel or ignition maps. Example is a Dodge Neon SRT4. If you run straight methanol, it will drop AF to 9:1 and lose power. If you run straight water then the engine leans out.. If you run "Mix" now you can tailor your AF targets up and down based on mix used.

On an application where tuning is available.. meaning changes to injector duty cycle.. straight alcohol is bullet proof.

Julio

I use pure meth on my high boost supercharged LT1. I never tried water because the pure meth works great in my application. I also run C16 so it helps alot even with the race gas. I'm sure water works fine or maybe even better in some applications. I don't think we can say it only works on the turbo GN applications. I see IATs over 300 on a 1/4 pass (NO IC) All the logs I have are with the iat before my alky nozzles so I don't have hard data on how much it actually cools the charge. I do spray a good amount of meth with two big nozzles and high pressure so some of the alky is used as fuel but with my 95# injectors running over 80% duty cycle it can't be much.

There is one situation where water is better. Pump Gas Drags doesn't allow Methanol (for obvious reasons), but they do allow water.

Anyone have any idea how denatured alcohol compares to Methanol?

Ethanol does not have as high a heat of vaporization as methanol.

Rich

OK.
So if I am understanding correctly, for making power, it is better than water because it will function as a fuel enrichment, but not as good as methanol?

What about injecting nitromethane and water?

What about injecting nitromethane?

That's sort of like injecting Nitrous. The discussion here centers around using water or methanol to reduce the chance of detonation and make the engine safer. Nitrous and nitromethane will not accomplish these goals.

Ok then, nitro and water. Or nitro, methanol and water?

Ok then, nitro and water. Or nitro, methanol and water?

Sounds like a plan.. go for it.. let us know how it goes ;)

1 rule of thumb, when an alky funny car can run faster on water i will switch...until then 100% meth ;)

No ;)

LOL hey i am happy running 100% meth......

That's great, you are one circumstance. As Mark pointed out, water injection isn't simply for auto 6 and 8 cylinder engines. Arguing an entire concept and theory on such a small set of circumstances is questionable. It might very well be that these engines operate behind or beyond the practical purposes of water injection, but that still does not invalidate water injection as it relates to internal combustion engines.

The system that has been outlined by most of you all is merely a supplemental fuel injection. This would be nearly the same as injecting or running 100% race gas. If I put water in my gas tank and said, "man it sure runs better on straight pump gas," you would call me an idiot. I passed similar judgement on your post.


Just putting out there what works for me ;) I love my alkycontrol kit and Juilo has been nothing but great help,

Like allot of people pushing big numbers there is allot of money in these set up's and i want it to last a long time...if Juilo can get a Turbo T/A to last @30lbs of boost on stock block on 100% alky ..that's all i need to here.... :cool:

That's great, you are one circumstance. As Mark pointed out, water injection isn't simply for auto 6 and 8 cylinder engines. Arguing an entire concept and theory on such a small set of circumstances is questionable. It might very well be that these engines operate behind or beyond the practical purposes of water injection, but that still does not invalidate water injection as it relates to internal combustion engines.

The system that has been outlined by most of you all is merely a supplemental fuel injection. This would be nearly the same as injecting or running 100% race gas. If I put water in my gas tank and said, "man it sure runs better on straight pump gas," you would call me an idiot. I passed similar judgement on your post.


Yep, I bet any of our cars would run better on straight methanol than on any combination of gasoline and water, water/methanol, or straight methanol injection. Unfortunately, that isn't practical and doesn't shed any light on the subject anyway. The principles of the IC engine have not changed since WWII. I advise those of you who are sincerely interested in this topic to go back and look at the original research on boost fluids. They decided on a water/methanol mixture. Go figure?

Rich

I have downloaded probably close to 60 papers that pertain to performance and forced induction with the bulk of the research done in the 40's. When I was is my teens and early 20's I would have probably ignored this stuff because after all its 60 plus years old. Now with more experience I realize that what used to work still does. Water is still water, methanol is still methanol and boost is still boost. About the only thing that is different about some of these airplane engines is that they run lower compression and rpm than we do, but they're also operated at max or near max load for extended periods of time and many are aircooled.


These engineering studies were done with the utmost seriousness as our air superiority was at stake. Most of these at one time were restricted access at minumum as the government realized the importance of the information. Nearly all studies you'll read mention detonation-limited performance as that is the stumbling block.

In an area where every pound counts if straight methanol was appropriate they would have used it because its 25% lighter than water. They of course found that methanol is prone to pre-ignition (where if you were to remove spark the engine would continue to run) and pre-ignition is particularly bad in a boosted engine as an intake "backfire" can have serious consequences.

I should mention outright that I never emailed Julio for the FAST logger files because I know their limitations and they won't include temp data other than a single IAT, there just isn't a way to hook up auxilliary thermistors to a FAST.

I doubt many here already running straight methanol will change their setup due to a post, but my hope is that people new to water injection will understand why a 50% mixture is both safer and more effective at controlling detonation than straight methanol. Don't run methanol because it sounds cool. When you do something, do it for an informed reason.

What it comes down to guys, we all are going to run what we feel is right....There is allot of great info on here. I am happy with my meth, Rich is happy with his 50/50 mix...

I think the engineers in this thread are bench racing with injection.

Vs guys like myself and Schurters LT1 have used it with positive track and dyno results.

So do you believe papers.. or do you believe real world results. Argue what you will.. 1,000's of cars running 100% straight methanol injection with positive results. For what ever the reason.. Is what it is. When you tune something with some balls on it once.. you never go back to water anything. Never.

I have never had a shop tell me ya know we tried this(straight methanol) and found water worked better. Lidio from Alternative was so in dislike from the water systems he had done, it was like getting a crowbar to get him to try 100% methanol or any other injection system.. why becuase of the issues this thread is about. And the information contained wherein. Once he tuned his first car on straight meth injection... he never looked back. www.alternativeauto.com he actually made an article on the fact.

Its really simple.. put you car on some rollers.. a few hours latter you will know the truth. This is assumming you can tune your ecu and have the facilities/resources to do so.

If not.. stop with the poison. :bow: Until you have the raw data.

cool stuff...but curious, whats wrong with the term alky injection? isnt that short for alcohol (methanol) injection?

actually alcohol in most would be much more associated with ethanol than methanol, but both are alcohols. I don't know if people use ethanol injection or not.

I think the engineers in this thread are bench racing with injection.

HEY! I take offense to that!

So do you believe papers.. or do you believe real world results. Argue what you will.. 1,000's of cars running 100% straight methanol injection with positive results.

Isn't one DSM guy running 45 psi boost with alky/pump gas? I think that should be the benchmark/poster child for 100% Meth. To anyone advocating the use of 50/50, that is your challenge. Get 45 psi boost safely with 50/50+pump gas, then I'll change my mind.

Mike

Julio: I think I spend as much or more time on the dyno and at track as most, if not more. Like I said, I guess we are going to have to agree to disagree on this one.

Rich

I guess the (how many thousands of) aircraft built mean absolutely nothing.

They weren't exactly running 45 psi boost, either, were they? Perhaps the water/methanol mix was adequate to achieve the desired safety factor at boost levels much lower than this.

it might be valid for the case in point, but not all encompassing.

This is actually a good point. I believe the 45 psi boost DSM more closely matches what we're working with than a 1942 airplane engine.

Hmmm, gonna have to read the rest of this thread later. :)

Cliff's Notes: If I hear "alky injection" one more time I am going to scream. Call it WATER injection or go home.
Why? My Grand National has a straight methanol injection setup, no water involved. Why would I call it water injection?

Hmmm, gonna have to read the rest of this thread later. :)


Why? My Grand National has a straight methanol injection setup, no water involved. Why would I call it water injection?



SCREAM!!!

HEY! I take offense to that!



Isn't one DSM guy running 45 psi boost with alky/pump gas? I think that should be the benchmark/poster child for 100% Meth. To anyone advocating the use of 50/50, that is your challenge. Get 45 psi boost safely with 50/50+pump gas, then I'll change my mind.

Mike

Ohh just throwing some ants on the cake :D

YES.. locally there is a 240Z with a GT42 turbo upwards of 40 PSI on 93 octane +(injection :) ) .. The DSM guys.. 40 PSI is old news..

Everything has a place, including non-alcoholic beer ;)

Maybe its the AEM's these cars are tuning with and 5 bar MAP sensors :bow:

JakeRobb.. Good Kill

Rich you set yourself up for this when you started the thread :) I tell you what when I get my car back together I will do a little experiment with water and let you all know how it goes. I currently run C16 and straight meth works for me. My car made north of 800RWHP with the old set up the new one should make at least a 100 more. My car was one of the fasteset lt1 s around last year, this year it will be well into the 8s. So this will be a good test on a very aggresive LT1 setup. I r an Injuneer to if that matters to anybody ;)

This is actually a good point. I believe the 45 psi boost DSM more closely matches what we're working with than a 1942 airplane engine.


Yeah but on a Powerdyne SC LT1 boosting to 5 PSI that water injection works great :p

Depends on means, situations not being extreme.. vs extreme situations(40 PSI). If the engine in question barely needs injection.. water and mixes thereof can be used to suppress detonation effectively including straight methanol. If the situation is extreme(40PSI) then the use of water is a no-no.

Show me different :) Dyno sheets, datalogs, track performance, etc.

No Data=no proof

Jeff: I'm sure it's obvious to you. But in case it isn't to others reading the thread: If you simply simply switch from methanol to water/methanol you will not see any gain unless it is already detonating with the methanol. And obviously, you will need to add fuel to replace the methanol to avoid a lean condition. Where the water might show gains is if using it allows you to raise the boost even further. This assumes you are not already maxing the blower out, the parts are mechanically strong enough to handle the boost, etc. No one is saying water is a panacea, just that a water/methanol mixture has more potential as a boost fluid under the right circumstances.

Rich

Rich you set yourself up for this when you started the thread :) I tell you what when I get my car back together I will do a little experiment with water and let you all know how it goes. I currently run C16 and straight meth works for me. My car made north of 800RWHP with the old set up the new one should make at least a 100 more. My car was one of the fasteset lt1 s around last year, this year it will be well into the 8s. So this will be a good test on a very aggresive LT1 setup. I r an Injuneer to if that matters to anybody ;)

Well there varying degree's.. on the internet.. you have to watch out :bow:

I B an Injuneer as well.. not a train one either :eek:

The test procedure would be simple enough in concept, just expensive and time consuming to implement. You would need a variable compression engine with the ability to vary boost over a wide range. A variety of different fuels would be needed. You would need a knock sensor and a dyno. For a given fuel you could easily establish a tune (including varying the boost level, CR, timing, AF ratio, etc.) that would produce max hp without knock. Then do the same with straight methanol and the water/methanol mix.

Of course, why bother since it's already been done?

Rich

I was planning on trying a little water anyway because I'm planning to run the standing mile at a hot rod event this spring. I'm hoping to keep the engine together for a whole mile and shooting for over 200mph. I have a built T56 ready to slap in and give her hell. My hope is the water will help keep intake and combustion temps down. I'm also very curious about how much power my TH400 sucks out vs the T56 so I will have a bunch of dyno testing to do should be fun!

Julio I have never driven a train but that does sound cool :cool:

Of course, why bother since it's already been done?

Rich

Because I R and Injuneer and don't beleive the tests! I do similar things for a living and have thrown many tests done by respected sceintist in the garbage. Many of the tests that are performed are in labs in an ideal environment. I try to repoduce these results in real world environments and never get the same results. In many cases I completly turn there recommendations upside-down.

It must all be BS then. I give up. Shame on an engineer for wanting to control his environment so he can demonstrate repeatable results. I suppose the same can be said for engine development on dynos that feature an environmentally controlled room so results before and after lunch can be comparable or even weeks later.

It must all be BS then. I give up. Shame on an engineer for wanting to control his environment so he can demonstrate repeatable results. I suppose the same can be said for engine development on dynos that feature an environmentally controlled room so results before and after lunch can be comparable or even weeks later.

You said it all thank you! The problem is these tests are in ideal conditions I never doubt the data I get. I apply tests in a real world environment most labs do not! I don't race my car in a lab or on a dyno. I race at the track in varying environmental conditions. The final tweaking on a tune is always done at the track it never comes off the dyno perfect.

The dyno is a development tool and if properly applied it will allow you to isolate a particular area of interest and present you with the results. Its a given that most of us are interested in the vehicle's performance at the track. The track being the "chassis" dyno where its proven out and you work on the suspension, fine tune and deal with the variables that are presented every trip down the strip or around the road coarse etc.

I honestly don't understand where you're coming from with poopooing research that is done in a uniform way, isolating the variables that may change an engine's propensity to detonation.

I think the point is that most of the hard work has already been done years ago. If you find that drowning the engine in methanol gives you the best results then by all means do what you feel most comfortable doing. I'm not going to shake my finger at anyone. Know this though, the research is real and it pertains to us whether its age or methology agrees with you or not. The database of engineering studies is only worth what one is willing to do with it.

Thanks for the topic Rich!

Direct from the procharger site "Before any ProCharger system is made available, it must pass a rigorous series of performance testing hurdles. All of our applications are proven on the dyno, in the lab and on the track before we will bring it to market."

This is what I'm trying to say many tests are performed in labs but that is only one part of testing. The problem I have is so many of these tests are qouted as gospel but do not work well in a real world environment.

The qoute I used from Procharger is exactly the reason I use their product they test it. Now go ask your engineers if they have devoloped a product that was impressive in the lab but never made it to market because it didn't perform as expected in the other testing. The answer is YES!

I think everyone understands that concepts proven in the lab need to be verified in the real world.

Mark: thanks! I agree that it has been interesting to get the different viewpoints out there. I doubt any minds were changed, but at least some opinions are out there for newbs to using boost fluids to consider. If this were my forum, I'd sticky the thread. I will suggest that to the mod here.

Rich

My Grand National has a straight methanol injection setup, no water involved. Why would I call it water injection?
SCREAM!!!
JakeRobb.. Good Kill
:lol:

But seriously, I'm asking. Why shouldn't I call meth injection meth injection? I totally accept the possibility that water+meth could yield better results (pending proof, like everyone else here), but why should I call the system I'm using by a misleading/inaccurate name?

That's what I really want to know.

:lol:

But seriously, I'm asking. Why shouldn't I call meth injection meth injection? I totally accept the possibility that water+meth could yield better results (pending proof, like everyone else here), but why should I call the system I'm using by a misleading/inaccurate name?

That's what I really want to know.

You can call it something other than water injection only if you have no concern for my feelings, you brute ;)

Rich

Engine detonates hard in street car while testing various internal coolants, engine breaks (head gasket, piston etc.) and requires an inconvenient tow home while hopefully learning something.

Engine detonates hard in an airplane while in flight while testing various internal coolants in hope of increasing maximum performance of aircraft for the war effort. Engines breaks, pilot has nowhere safe to land away from population and must try to ditch aircraft in a way so as not to injure or kill someone. Pilot must take plane all the way down auguring it into the ground. Pilot dies, data recorder destroyed, family and friends grieve everybody asks why this had to happen.

Reply, somebody on CamaroZ28.com didn't believe knowledge gained from a controlled test.

just kidding, really. Thanks for the conversation.

Mark

Mark, I didn't say that the water doesn't work in the WWII planes. What I did say is this test does not prove that it works with our cars. I have seen many nearly identicly prepared LT1s that made different amounts of power and required different tweaks in the tuning to produce max power. Every one of these damn cars wants something a little different.

To close the water or alky argument once and for all I will use something we all understand BEER! Beer is an alchoholic beverage even though it contains far more water than alchohol. SO this goes against the water argument if your not running 100% water it is indeed ALKY injection Dammitt! Don't you dare start arguing about beer :cool:

Engine detonates hard in an airplane while in flight while testing various internal coolants in hope of increasing maximum performance of aircraft for the war effort. Engines breaks, pilot has nowhere safe to land away from population and must try to ditch aircraft in a way so as not to injure or kill someone. Pilot must take plane all the way down auguring it into the ground. Pilot dies, data recorder destroyed, family and friends grieve everybody asks why this had to happen.


Mark

Hopefully they had two engines when they were testing boost coolers in flight.LOL:)

I would guess cost was a major factor in the decision making for planes... cost of water consumption versus methanol.

Mark, I didn't say that the water doesn't work in the WWII planes. What I did say is this test does not prove that it works with our cars. I have seen many nearly identicly prepared LT1s that made different amounts of power and required different tweaks in the tuning to produce max power. Every one of these damn cars wants something a little different.

To close the water or alky argument once and for all I will use something we all understand BEER! Beer is an alchoholic beverage even though it contains far more water than alchohol. SO this goes against the water argument if your not running 100% water it is indeed ALKY injection Dammitt! Don't you dare start arguing about beer :cool:


Ever been to a japaneese steak house and have the chef pour light beer on the grill? Fires right off in flame. Pretty amazing considering its only 5% alcohol by volume. hmmm.....light beer injection.....

I would guess cost was a major factor in the decision making for planes... cost of water consumption versus methanol.


Yes and making methanol available for the planes would be a logistical nightmare. Can you imagine "We ran out of methanol now the planes are all grounded."

The military uses one single fuel (JP8) for M1A1 tanks, Apache Helicopters, 5 ton trucks, HEMMT's and Humvees. They use one fuel to keep things logistically simple and inexpensive not because JP8 is the best fuel.:)

Non-alcoholic beer=water injection
Beer=water/mix injection
Bourbon=Alky injection

A few in the test group felt they got drunk drinking the non-alcoholic beer.;)

Hows that :D

Non-alcoholic beer=water injection
Beer=water/mix injection
Bourbon=Alky injection

A few in the test group felt they got drunk drinking the non-alcoholic beer.;)

Hows that :D

For personal consumption I am in your camp, Julio - EtOH "injection" all the way! That beer stuff is for sissies and girls. Especially "light" beer. Bleech. They say methanol is a great high too, but if it doesn't kill you it will make you blind. :p

BTW: as far as logistics, the military used a methanol:water mix, so they had to supply methanol anyway. Methanol is cheap and easy to produce in industrial quantities. It is now made from natural gas but can be easily produced by fermenting wood (hence the term "wood alcohol") and can also be produced from coal. I don't know how they made it in WWII. In the long term, there is plenty of it: In 2006 astronomers using the MERLIN array of radio telescopes at Jodrell Bank Observatory discovered a huge cloud of methanol in space. The cloud measures 300 billion miles across, and is emitted from stars as they form.

Rich

For personal consumption I am in your camp, Julio - EtOH "injection" all the way! That beer stuff is for sissies and girls. Especially "light" beer. Bleech. They say methanol is a great high too, but if it doesn't kill you it will make you blind. :p

BTW: as far as logistics, the military used a methanol:water mix, so they had to supply methanol anyway. Methanol is cheap and easy to produce in industrial quantities. It is now made from natural gas but can be easily produced by fermenting wood (hence the term "wood alcohol") and can also be produced from coal. I don't know how they made it in WWII. In the long term, there is plenty of it: In 2006 astronomers using the MERLIN array of radio telescopes at Jodrell Bank Observatory discovered a huge cloud of methanol in space. The cloud measures 300 billion miles across, and is emitted from stars as they form.

Rich

You mean that goofy methanol deposit in the Corona Borealis galaxy? That thing is some 400 million parsecs away (1 parsec=20 trillion miles) and the light from it is over a billion years old, so it might not be there anymore, LOL.

I think this discussion has really been good (up to this point), but I still don't know what to run in my car, although I'm tempted to try a larger meth concentration to see where that gets me.

Does Water Injection Increase Cylinder Pressure?

Does Water Injection Increase Cylinder Pressure?


I suppose it does, as would methanol when it phase changes from liquid to gas.

Rich

I'm asking because i'm running 7lbs on the stock LT1 bottom end and looking for more power without speeding up the inevidable.I'm only able to run about 18 degrees of timing right now. In my situation would this be a route i should take.

Here's a good short article on water injection:

http://autospeed.drive.com.au/cms/A_107970/article.html

I still like this topic.

Someone needs to change the title why its alky injection;)

Someone needs to change the title why its alky injection;)


Some how i don't think Rich is up for that;)

Methanol
RON 106
MON 92

C16
MON 117
RON ???

C16 has a much higher MON than methanol. But methanol has a much higher (~4X) the heat of vaporization of gasoline. That is why it is such an attractive fuel for a blower car - it can eliminate the need for an intercooler. The other reason is that the eenrgy content of methanol of an optimal methanol:air mixture is ~10% greater than for gas.

You would be better off running a blower car with straight methanol than with race gas. So, if you add enough methanol to your mixture, I guess you could approach this. Is this what Julio is doing? What would happen with a methanol/water mixture as the primary fuel? Would it allow even higher boost???

Rich



I thought methanol is 116 octang?

I thought methanol is 116 octang?

Thanks for the link at the bottom of your post!

MarkinKC69Z - I still like this topic, too.

Methanol is ~100 octane when tested by the standard method. However, due to the cooling effect of the high heat of vaporization when used as the primary fuel it has detonation resistance of a much higher octane gasoline. When used as an injection fuel, the effect on detonation resistance has not been well quantified. IOW, I doubt if any of us hobbyists ever defined an appropriate test procedure and then ran the tests with differing mixtures of water/methanol. Most of what we know is rule of thumb stuff.

But technnically speaking, the octane rating of methanol is ~100 with the MON and RON as stated.

Rich

HOW DO YOU DETERMINE OCTANE?
Ok, then, how is octane rating determined? First, you go out and get a suitable supply of the fuel which you wish to test. Then, you get yourself some heptane (made from pine sap) and some iso-octane (a petroleum derivative). Finally, you and your buddies arbitrarily, agree that iso-octane has an octane rating of 100 while heptane has an octane rating of 0.

Next, you call up Waukesha Motors and order yourself an ASTM-CFR test engine. Make sure you have about $250,000 available on your VISA before you order it. This single-cylinder wonder has a four bowl carburetor and a movable cylinder head that can vary the compression ratio between 4:1 to 18:1 while the engine is running.

You fill the ASTM-CFR full of your mystery fuel and, for automotive fuels, you run two test protocols using the ASTM. One protocol is called the motor protocol and the other the research protocol. You vary the compression ratio until the onset of knock and write down all kinds of various scientific parameters.

Next, you run your reference fuel, made up of various proportions of heptane and iso-octane through the ASTM-CFR. You keep varying the proportion of heptane to iso-octane until you get a fuel that behaves just like (knock-wise) your mystery fuel. Once you get that, you say to yourself "How much heptane did I have to add to the iso-octane to get the mixture to knock in the ASTM-CFR just like my mystery fuel?" If the answer is, say, 10% heptane to 90% iso-octane, your mystery fuel has an octane number of 90.

How do the motor and research protocol differ? Mostly in input parameters. In the motor protocol (ASTM D2700-92), the input air temp is maintained at 38C, the ignition timing varies with compression ratio between 14 and 26 degrees BTDC, and the motor is run at 900 RPM. In the research protocol (ASTM D2699-92) the input air temperature varies between 20C and 52C (depending on barometric pressure), timing is fixed at 13 degrees BTDC, and the motor is run at 600RPM.

The motor method, developed in the 1920s, was the first octane rating method devised. After its introduction, many more methods were introduced. During the 1940s through the 1960s one of those methods, the research method, was found to more closely correlate with the fuels and vehicles then available. However, in the early 1970s automobiles running on high-speed roads, such as the German Autobahn, started destroying themselves from high-speed knock. It was found that the difference in ratings between the research and motor method, known as the fuel's sensitivity was important as well. The greater the fuel's sensitivity, the worse it performed from a knock point of view in demanding, real-world, applications.

Remember, at the pumps, the results of the motor and research numbers are averaged together to get the value you see. The fuel's sensitivity is not published. Highly cracked fuels have high sensitivity while paraffinic fuels often show near zero difference between the two. While the fuel's sensitivity is not published at the pump it can be a valuable indicator as to the fuel's real world octane performance. Remember, the octane tests are conducted in a lab using a special test engine; the lower the fuel's sensitivity, the more likely it is that the fuel will, indeed, behave as expected. Generally, the closer the fuel's research rating to the published rating the more reliable the published rating. Because the motor and research methods primarily differ in terms of input parameters (the test engine is the same for both), the greater difference that a fuel exhibits between its motor and research test will be due to differences in input parameters (intake temp, timing, etc.). A fuel that has an octane rating that varies with intake parameters is said to be more "sensitive."

Lifted from http://www.prime-mover.org/Engines/GArticles/octane.html

Rich

Now if only we could get people to agree on the octane rating of methanol instead of inflating it to 116 or whatever.

Thanks for the cut and paste, it was an informative refresher. Luckily there are companies out there that will do the testing for a fee.

BTW, there is a whole different test procedure for determining octane over 100.

FWIW, as a practical matter, with a high VE NA engine max hp is seen in the range of 14:1 CR, IF detonation can be avoided by using a fuel of sufficient octane. Both high octane race gas and M100 can be used sucessfully in such an engine. 116 octane is not needed for that CR, many people use fuels in the 112 octane range. "Restricted" applications run as high as 17:1 and also do not need extremely high octane - however, forced induction motors do.

Rich

Yes, anything over 100 octane is acutally inferred and not directly measured.

BTW, there is a whole different test procedure for determining octane over 100.

FWIW, as a practical matter, with a high VE NA engine max hp is seen in the range of 14:1 CR, IF detonation can be avoided by using a fuel of sufficient octane. Both high octane race gas and M100 can be used sucessfully in such an engine. 116 octane is not needed for that CR, many people use fuels in the 112 octane range. "Restricted" applications run as high as 17:1 and also do not need extremely high octane - however, forced induction motors do.

Rich

Very good advice. You should get out sometime though...it'll help you out a lot.

"your heart is free...have the courage to follow her!!" Uncle Argile-Braveheart

:D :D

Water is unlimited octane

And refer to the Honda Formula One program where they ran engines at 60 PSI boost making in excess of 1300 HP on a 4cyl.. Top Alcohol Dragsters.. etc.. running insane cylinder pressures.. on methanol.

Who cares what the octane is. :bow:

I just read this whole thing and have to ask a question: If you cool the air temperature in the intake by some means on a supercharged car, will there actually be more moles of oxygen in the intake at this lower temperature than there were at the previous higher temperature? (If you don't change anything, nothing, except the temperature of the air in the intake.) I would think that maybe with the pressure on the high side of the supercharger reduced due to the lower temperature, it might be able to push more moles of gas in there .
I have some other ideas but I'll keep this short.

Blowers "blow" better than they "suck". So that's one reason to put the heat exchanger on the outlet side of the blower rather than the intake side. The flow restriction is less important there. The main one though is that it's much easier to cool hot air (on the pressure side) than to cool already cool air on the intake side. If I knew any thermodynamics, I could explain it better.

Rich

If you cool the air temperature in the intake by some means on a supercharged car, will there actually be more moles of oxygen in the intake at this lower temperature than there were at the previous higher temperature? (If you don't change anything, nothing, except the temperature of the air in the intake.) I would think that maybe with the pressure on the high side of the supercharger reduced due to the lower temperature, it might be able to push more moles of gas in there .
I have some other ideas but I'll keep this short.

You're thinking correctly, but not for meth or water injection.

With an intercooler, you cool the air at the discharge of the compressor. This makes it contract and the pressure drops. The lower pressure means the compressor has to overcome less dP so the flow increases and so does the power.

With water or Meth injection, you cool the air by injecting a liquid. The air contracts, but the extra space available is filled in with flashed liquid, so the pressure does not change. No change in pressure means no change in flow and no change in power. Now, increase the boost or timing, and you get the extra power.

Mike

I've known some thermodynamics for years, but I only recently grasped exactly why spraying a liquid cools the surrounding air. A lot of the real explanations for things like that just aren't given in the textbooks.
I overlooked that about the decreased temperature not resulting in lowered pressure due to the introduction of more gas. I was going to say that if the pressure was lowered than one would think that water injection alone with no other changes would increase power.

Wow, are you guys lucky I found your thread so I could explain yourselves to one another.

First off, Julio (the Buick V6) guy is most likely using Methanol injection not just for detonation prevention, but for FUELING at least part of his combustion. So yes, replacing his fuel with water, in any ratio, will cause a drop in power as he notes.

The LSx guys are talking about water/methanol injection for a car that is already adequately fueled, but without enough octane to support the heat and pressure.

In the case where you're adequately fueled, water is preferred. In the case where you're actually injecting something to support combustion, something flammable (ie: methanol) is preferred.

It really took 9 pages of this thread to get here?

When you're doing it for combustion, call it methanol injection. When you're doing it to reduce temperatures, call it water injection. I have spoken.

Yes, thanks for educating us :rolleyes:

We understand the difference between the two. We were arguing the merits of each.

I'd like to better understand which setup (straight water, mix, straight meth) has potential to make the most power on pumpgas-93.

If you were to build a combo from scratch to get the most out of FI on pump, which fluid do you pursue?

What are most high horsepower pumpgas guys running?

Thanks,
Scott.

Well, your post opens up the same debate people have already expressed opinions on. I think I stated mine pretty clearly. Straight water and mixtures of water:methanol or even straight methanol significantly lower combustion temperature and allow either more boost or higher compression. Straight water has the greatest effect on combustion temperature/volume injected. Mixtures of up to 50% methanol provide most of the benefits of straight water in terms of reducing temperature and also have a much lower freezing point in addition to allowing larger volumes to be injected (because the methanol burns as a fuel). As the methanol:water ratio rises over 1:1, the loss of cooling effect offsets the greater volume you can inject without excessively inhibiting combustion. Therefore the ideal mixture is ~1:1 water:methanol. Also, it's really best to think of it as a mixture of gasoline, methanol, and water. The ideal combination for a particular gasoline is going to differ. Of course, what works best is setting up to car to run on straight methanol. This is not practical for a street car though :(

IMHO.

Rich

Thanks Rich,

I didn't realize (or maybe I had forgotten) there were so many good posts leading up to the current to which I replied.

Thanks again for your support!

-Scott.