straight water vs Methanol or a Methanol mixture

[boostm3]

>>BLAH,... BLAH,.... ......BLAH............... ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ<<

Now thats what I call an intellegent comment Brilliant, reallly... Guess ol 'Redregal needed to put all his braincells to work to come up with that one. And, the nice thing is, it adds Soo Much to the dialog

 

[1badTTA]

BoostM3, have you sh**canned your overpriced aquamist pump and replaced it with a $60 shurflo pump so you can run pure methanol? Didn't think so.

Just wondering but have you read the rulebook for the ralley cars? Wondering what it says about acceptable fuels and if Methanol is legal. Haven't seen too many sanctioning bodies that don't have rules about what you can use for fuel and since methanol is a fuel, it would be banned from most races unlike water which isn't a fuel.

Anything else I can answer for you? (if you even read this far down this post)

 

[boostm3]

>>Just wondering but have you read the rulebook for the ralley cars<<

1bad, you bring up an interesting point. I dont have the answer for you.

BTW, I trust you accepted the information I posted proving that water is the better coolant vis a vis the difference in the Latent Heat of Vaporization values between water and methanol.... Given that this is fact, not theory, what are your thoughts as to why alcohol injection is more effective for your car than water injection, or a mixture?

 

[1badTTA]

Edit: Water actually does cool the charge before it enters the cylinder, Alcohol cools it more though.

Originally posted by 1badTTA
Well maybe it is because the Alky actually cools the charge air BEFORE it enters the cylinder, and then the fuel (Alky and Gasoline mixture) burns cooler at a correct AFR than just Gasoline. Now Water alone being added to the combustion cycle will only absorb heat inside the cylinder and is simply replacing some of the space taken up by the air fuel mixture which actually makes the power. Once the cylinder temps are lowerd enough by the water, adding more will reduce power. Alcohol on the otherhand is actually making more power with every increase of its amount by cooling the charge more and also burning cooler in the cylinder. You are replacing gasoline with alcohol to get the correct AFR but that AFR is also needing to be changed due to Alky needing a different AFR than Gasoline. The final result when you have the right amount of Gasoline, Air, and Alky is a complete burn inside the cylinder with a larger amount of air (hence the more power) at a lower temperature than just air and gasoline (hence the reduced detonation).

So what about that goes beyond the laws of physics?

I told you that you weren't reading the posts completely

 

[Jon E]

I dont think that knock suppression behaves the same on each and every combination. You have to take into account all sorts of variables like air charge temp, EGT's, combustion chamber design, the shape and speed of the flame front etc. I think the fact that the TR's are already intercooled has a lot to do with why 100% alky works better for them. They dont need any extra cooling in the combustion chamber, their already cool enough as it is. Thats where the supercooling of the intake air from the alky becomes more effective for them at reducing knock.

I think water is better suited for hot air setups where heat reduction in the chamber reduces knock the best and alky works better in intercooled engines by supercooling the air charge even more without taking up space in the chamber. There is no one cure for everyone you just have to find out what your vehicle needs the most and use it.

I dunno...I could be wrong...I have been before.

 

[TurboSy]

Derek OBanion wrote this a while back on the AEM forum, might help explain why methanol works so well.



JC, all you said is correct. Except you said 19000 BTU/gal and 9800 BTU/gal. You made a little typo. It's 19000 Btu/lb and 9800 Btu/lb. Mass, not volume. Anyway.......

Methanol makes more power party due to the charge air cooling. However, you are just leaving out the second part of the equation. The specific energy of methanol, the maximum amount of BTUs that can be created with a given mass air flow, is greater than gasoline.

Let's see why. Now keep in mind the following results DO NOT take into account charge air cooling. That benefit is left out. These are based on a static mass air flow. I'll use your figures for BTU/lb.

At stoich (14.7 vs 6.45):

19000/14.7=1292 BTU/lb for gasoline
9800/6.45=1519 BTU/lb for methanol

1519/1292=1.176 or 17.6% more BTUs are created by a stoich mixture of methanol vs gasoline.

Ah....but it gets better. Methanol has far better flammability limits. Which means it continues creating power, in relatively richer mixtures than gasoline.

Gasoline won't make any more power past 12:1, which is 22.5% richer than stoich. That's pretty much universally agreed on. We can agree on that yes?

Methanol makes maximum power at 5:1, which is 30% richer than stoich. Donald Wang said 4:1, but that may be optimistic, so I'm using a conservative figure.

19000/12=1583 BTU/lb
9800/5=1960 BTU/lb

1960/1583=1.238 or 23.8% more power

There you go. That's why.

So it's 23.8% more power, before you even count the charge air cooling, which drops my temps from 80F to 20F or lower. That's about 15% increase in charge air density right there, on top of the 23.8% increase in chemical power. I will admit the 23.8% figure has to be corrected for the ratio of power created by gas vs methanol. 23.8% gain is assuming 100% methanolo fueling, which isn't the case with my injection kit.

All the while you have reduced peak cylinder pressures and temperatures, which makes things easier on the pistons, rods, crank, valves, turbine, etc.

The stuff is AWESOME. How else can I say it?
_________________

 

[WFO]

Originally posted by TurboSy
Derek OBanion wrote this a while back on the AEM forum, might help explain why methanol works so well.

Derek O'Banion=AnArKey=the guy who's supra i was in reading mid 30º charge air temps.

He told me later that he was seeing lower temps than we saw that night once he got it tuned a little better.

later,sean

 

[AnArKey]

Hi guys. Guess I made it into this thread eh?

To confound things, I have made a switch to 50/50. Mainly because I can get similar knock elimination with less total flow. I may jack the flow back up, and run a 80/20 or 90/10 mix. I discovered that methanol really doesn't do combustion chamber cleaning, it's water turned to steam that actually does that. So I know I at least want some water.

About H202 injection, I have looked into it. It won't make a difference. Using store bought H202 won't have enough oxygen in it to raise power even 1%. You would need at least 10% actual H202 in the mix to really start gaining power. Kinda hard considering the stuff at the store is only like 2-3% actual H202.

 

[sstock]

1994 Lightning supercharged 11psi:
12.29@110MPH Race gas 26 degrees timing
12.65@107MPH Race gas 29 degrees with M3 and M7 nozzle running 70% ISO.

Water slows you down period! End of story no disputing that in my application.
My conclusion is this: At the track there is no substitute for race gas.
On the street, Alky/water allows me to run 6-8 degrees more timing without knock and allows for a better setup with 92 Octane pump gas.

At the track, leave water in the water fountain.

Later
sTeve

 

[AnArKey]

H2O2 revisted. I didn't know you could buy it at 35% or 50% concentration. NOW we are talking. This promises to be as powerful a oxygenator as N20 can be. I'll start a thread about this too.

 

[Michael Johnson]

I've run all sorts of mixtures on my car with varying results. Three things that are extremely important when using 100% water is nozzle size, pump pressure and nozzle placement. A 1M nozzle @ 80-100 psi pressure will deliver plenty of water, in a very fine mist, to reduce intake temperatures and control detonation. This also eliminates any engine bogging. Also, it is important to inject where the air temperature is hottest, which for me is right at the blower discharge. Depending on boost levels, intake air temps drop up to 130 degrees when this is done. The hotter the air, the easier it is for the water to flash to steam and it allows for more efficient use of the water injected.

I've run 16 psi (this is allot for a KB blower without an intercooler) with a chip burned for 8 psi of boost using everything from 100% alky to 100% water and various mixtures of each. I've settled on straight water mostly for tuning reasons. It doesn't effect AFR at all and lets me have a more consistant tune. I also don't like the idea of tuning for the alky and then having a dead pump or clogged nozzle causing the engine to go very lean under boost. One other benefit is a 1/2 gallon tank of water will go a very long way.

Personally, I think the higher octane of the alcohol offsets it's reduced heat of vaporization. On the other hand, gasoline contains more energy which in turn has more hp potential per unit weight. All in all I think they are very close when the tune, nozzle size and injetion points are optimized for each. For me getting the AFR correct and consistent was hard enough using computer controlled fuel injectors. Adding an unmetered source of fuel was no something I wanted to deal with.

I'm not saying anyone is wrong but I just wanted to add my experience to this thread in regard to supercharged engines.

 

[boostm3]

Michael, a very intellegent viewpoint

For those who still think that Methanol cools as well, or better than water, here are the facts, like them or not:

Gasoline has a latent heat between 350-500 kJ/kg, water has 2257kJ/kg and methanol has 1109kJ/kg.

Therefore if removal of heat is your most important issue, youll use mostly water. If more fueling is your goal, youd be better off tuning it in with gasoline. For those who have compared accurately, and come to the conclusion that 100% methanol produces the most power, then its for reasons other than cooling that this is being achieved.

 

[sstock]

Michael,
I see you have made it over here from the corral as well.
I like this site because it offers a technical level that is hard to find on other UBB's, bet there are more Ford guys lurking than anyone else. In short the Buick guys have it figured out and know how to go fast and have fun. The propane stuff is real interesting.

I know you are a proponent of water and small nozzle and nice pressure. You like me have probably played around this stuff quite a bit.

You mention about water injection turning to steam, which caught my eye, and I said of course thats the answer! Steam is made when the vapor pressure of water is at or slightly above at the vapor pressure in the environment at the boil point.

Here at sea level it is 212 degrees at the correct barometer.
The properties of water when it goes to steam is expanding the volume by at least 1700 times. Thus 1 gallon of water = 1700 gallons of steam.

Now lets look at the air inlets of a typical compressor at say 8-9lbs of boost on a 80 degree day. At the very most 190 degrees.
In fact the Kenne you have with 16 psi would maybe make 250 degrees. Normally water would boil at that and make steam but you are over two atmospheres there and I don't think it is going to happen.

Correct me if I'm wrong, I didn't pull any reference books out just workin off the top of my head here, but I might be wrong.

At any rate, this makes for some good bench racing, and I would like to hear some other view points too.
Later
steve

 

[1badTTA]

Originally posted by sstock


You mention about water injection turning to steam, which caught my eye, and I said of course thats the answer! Steam is made when the vapor pressure of water is at or slightly above at the vapor pressure in the environment at the boil point.

Here at sea level it is 212 degrees at the correct barometer.
The properties of water when it goes to steam is expanding the volume by at least 1700 times. Thus 1 gallon of water = 1700 gallons of steam.

Now lets look at the air inlets of a typical compressor at say 8-9lbs of boost on a 80 degree day. At the very most 190 degrees.
In fact the Kenne you have with 16 psi would maybe make 250 degrees. Normally water would boil at that and make steam but you are over two atmospheres there and I don't think it is going to happen.

Correct me if I'm wrong, I didn't pull any reference books out just workin off the top of my head here, but I might be wrong.

At any rate, this makes for some good bench racing, and I would like to hear some other view points too.
Later
steve

Since you are saying that under those conditions water will not turn to steam, why is it so hard to boil water at a higher elevation? Just from what I know, it takes 9,000 btu of heat from a stove to boil a pan of water at sea level, I am at about 2500ft and it requires at least 9,300 btu to get the same pan of water boiling. Looking at this, I would have to guess that with 16psi and 250 degree inlet temps, you are going to see steam starting to form.

Just an obversation.

 

[sstock]

Since you are saying that under those conditions water will not turn to steam, why is it so hard to boil water at a higher elevation? Just from what I know, it takes 9,000 btu of heat from a stove to boil a pan of water at sea level, I am at about 2500ft and it requires at least 9,300 btu to get the same pan of water boiling.

Don't know about the BTU thing but for instance water boils in Denver at about 201 degrees F.

 

[Jon E]

The higher the barometric pressure, the higher the boiling point is. If you pull a vaccum on water, it will boil right in front of you and will eventually freeze too if you have enough vaccum. Whether the barometric pressure has an effect on its latent heat of vaporization I dont know, but it would be interesting to see.

 

[TurboSy]

Originally posted by boostm3
Michael, a very intellegent viewpoint

For those who still think that Methanol cools as well, or better than water, here are the facts, like them or not:

Gasoline has a latent heat between 350-500 kJ/kg, water has 2257kJ/kg and methanol has 1109kJ/kg.

Therefore if removal of heat is your most important issue, youll use mostly water. If more fueling is your goal, youd be better off tuning it in with gasoline. For those who have compared accurately, and come to the conclusion that 100% methanol produces the most power, then its for reasons other than cooling that this is being achieved.

Not sure anyone's arguing those facts, but if you can only inject 1/3 the amount, methanol would give you an overall better benefit in the cooling dept. Only down side I see is you'll have to fill up more often.

 

[cool 84]

I wish people would take the time to read this so we would have to quit repeating ourselves. NO ONE ARGUES WATER WILL ABSORB MORE HEAT THAN METHANOL GIVEN UNLIMITED TIME.

With that said, ALCOHOL EVAPORATES FASTER AND ABSORBS MORE HEAT IN A GIVEN TIME.

We're talking a second or two at most from the injection point to the combustion chamber.

THE ****ING CHARGE AIR GUAGE SITTING RIGHT IN FRONT OF ME THAT I WITNESSED WITH MY OWN EYES SHOWED A HUGE DECREASE IN CHARGE TEMPS WITH ALKY WHEN COMPARED TO WATER.

Pour water on your arm and blow on it. Then pour alcohol on your arm and blow on it and see which one is cooler. Yes, the water wil sit around longer and eventually take more heat out of your arm but alcohol will give a lot more cooling at first.
Water probably has more of an effect in the combustion chamber.

Anyone ever wonder why pure methanol burning blown/turbo cars don't use intercoolers? Ever notice that most have compression ratios ~14:1 and run 30+ psi boost.

Only so much water can be injected before putting out the fire. With Methanol you can keep injecting more and more as you need it and cut back on your fuel as necessary.

One last thing, water boils at a lower temp at high altitude. When I climbed Mt. Whitney, near the top ~14,000' I could just about hold my hand in the boiling water. It would barely get hot enough for cooking. Another example, how is it that newer cars can run temps in excess of 212 degress without boiling the water? Possibly the pressure it's under.

 

[Razor]

YAWN

Never convince someone that theyre beliefs are tainted..

Some play with water..some dont..enjoy your decisions..

 

[Michael Johnson]

sstock,

I've lurked around here for 2-1/2 years and as you can see I rarely make posts. I've had an SMC kit on my car for two years now and it's taken allot of tweeking to figure it out. At first I took a page out of the Turbo Buick book and ran the 15M nozzle and straight denatured alcohol. It worked OK in the upper rpm's but the car bogged in the lower/mid rpm's. Then a friend and I started messing with things. He did some temperature logging on his Novi blown '99 GT and found that using a 1M nozzle with high pump pressure gave the best air temp reductions. A larger nozzle did nothing to reduce temps and just robbed power. His discharge temps would drop from 230 degrees to about 95 degrees. I used a 3M nozzle and ran 16 psi with no detonation so I personally backed up his results. Because of the way a KB sits on a 5.0L it was very hard for me to get accurate temp readings but the results were very good. The key to using 100% water is to make a very fine mist which is done with a small nozzle and high pressure and use absolutely as little water as necessary.

IMO, spraying alcohol would provide the greatest potential for making hp but for my application it is much harder to tune a consistent AFR. Since I have no intercooler option I'm using the water to remove heat from the air charge.


cool 84,

You're right about alcohol evaporating faster than water but this is exactly why it removes less heat. Is takes much less water than alcohol to remove a given amount of heat. The secret it to atomize the water as much as possible. This greatly increases its evaporation rate. When a 1M nozzle sprays a mist at high pressure it is almost immediately absorbed by the air. When a very fine mist is injected into 200+ degree air it turns to a gas immediately and absorbs a lot of heat. Methanol is a far superior choice as a fuel over gasoline. It has allot of specific energy and a very high octane rating. IMO, it is the octane rating more than heat reduction that would allow it to make more hp than using gasoline and water. I would think injecting methanol would be a better choice for guys running very high boost levels and/or an engine with a high static compression ratio. For someone using it to perform like an intercooler (me) then 100% water is probably the best choice.


I still have a lot to learn about using water/alky injection. Heck, next year I might recommend filling the tank with Gatoraid.