School Me On Meth Install
02-20-2017, 12:45 AM
#21
Good discussion guys.
More than ModChevelle bargained for I'm sure!
I've honestly only tuned one turbo LS with meth injection. It was an Alky Control kit so it had no issues with the pure methanol.
We didn't know diddly about how to set the system up. The instructions were poor and we couldn't get ahold of the company.
It had two nozzles. So we started out with low boost and no meth for a baseline then turned it on and tested again.
In the end at 20psi the meth accounted for 15% of the fueling. Injectors were at 100% duty so we needed that extra fuel.
Never a hint of knock.
Funny though, a year later he had discovered an error in the connecting rods he chose and that engine was 8:1 CR.
The other cars I've tuned are all Hemi cars with Centri, Roots and turbos.
All use the Snow kit and boost juice which is a 50/50 mix.
I don't choose these systems, they are on the cars when they arrive.
On the Dodge, we can monitor knock sensor volts. Left and right bank.
So the effect of spraying water meth is pretty clear.
Roots blower cars have the IAT in the manifold under the A2W intercooler. So it sees the cooling effect.
In the other cars it might be before the IAT or after. Depends who built it.
On any of these cars, too rich kills power. And customers WANT those numbers.......
Hemi's btw are detonating sombitches. Personally, I think water meth would be smart on the NA cars!
I'll take our LS stuff any day.
Ron
More than ModChevelle bargained for I'm sure!
I've honestly only tuned one turbo LS with meth injection. It was an Alky Control kit so it had no issues with the pure methanol.
We didn't know diddly about how to set the system up. The instructions were poor and we couldn't get ahold of the company.
It had two nozzles. So we started out with low boost and no meth for a baseline then turned it on and tested again.
In the end at 20psi the meth accounted for 15% of the fueling. Injectors were at 100% duty so we needed that extra fuel.
Never a hint of knock.
Funny though, a year later he had discovered an error in the connecting rods he chose and that engine was 8:1 CR.
The other cars I've tuned are all Hemi cars with Centri, Roots and turbos.
All use the Snow kit and boost juice which is a 50/50 mix.
I don't choose these systems, they are on the cars when they arrive.
On the Dodge, we can monitor knock sensor volts. Left and right bank.
So the effect of spraying water meth is pretty clear.
Roots blower cars have the IAT in the manifold under the A2W intercooler. So it sees the cooling effect.
In the other cars it might be before the IAT or after. Depends who built it.
On any of these cars, too rich kills power. And customers WANT those numbers.......
Hemi's btw are detonating sombitches. Personally, I think water meth would be smart on the NA cars!
I'll take our LS stuff any day.
Ron
02-20-2017, 12:45 AM
#22
Restricted User
Does it? I get that Methanol carries it's own oxygen to the party. However, not enough to throw it's own party.
Isn't any additional fueling, beyond stoichiometric, essentially doing the same thing water would do? Absorbing heat and expanding, same as everything else in the combustion chamber. With forced induction it's not rare to see more fuel dumped into the engine than actually produces best power. It's used to keep things cool, and detonation at bay. But lacking oxygen to react with, it's not really "burning"... Or, is it?
Isn't any additional fueling, beyond stoichiometric, essentially doing the same thing water would do? Absorbing heat and expanding, same as everything else in the combustion chamber. With forced induction it's not rare to see more fuel dumped into the engine than actually produces best power. It's used to keep things cool, and detonation at bay. But lacking oxygen to react with, it's not really "burning"... Or, is it?
02-20-2017, 12:57 AM
#23
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And kind of the opposite to your statement... If it were that simple, we could all just run 87 octane at stoich and add water.
How about if you mix a little hydrogen peroxide in with your water/meth so the meth can actually burn?
02-20-2017, 06:42 AM
#24
While most of this is way over my 70 YO brain, Ron did bring up something interesting (maybe better worded jumps out at me, lol)-spraying before the IAT sensor, if it sees the cooling effect, does the sensor think I am driving in a snow storm, and with the ECU I am running (Holley HP) I would have to be concerned as to how much fueling I am adding in the tables for that given temp range-the data log might reveal what's going on.
Just to throw a wild card in here, I am adding a flex fuel sensor, I wonder if adding some E85 to the tank would be comparable to spraying meth.
I know, to much coffee already this morn, lol
Just to throw a wild card in here, I am adding a flex fuel sensor, I wonder if adding some E85 to the tank would be comparable to spraying meth.
I know, to much coffee already this morn, lol
02-20-2017, 08:11 AM
#25
TECH Enthusiast
You're right. It's almost never that simple. However, the point being, it's impossible to "burn" the fuel without sufficient oxygen to react with. So, what's the fuel doing?
And kind of the opposite to your statement... If it were that simple, we could all just run 87 octane at stoich and add water.
How about if you mix a little hydrogen peroxide in with your water/meth so the meth can actually burn?
And kind of the opposite to your statement... If it were that simple, we could all just run 87 octane at stoich and add water.
How about if you mix a little hydrogen peroxide in with your water/meth so the meth can actually burn?
02-20-2017, 08:47 AM
#26
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The methanol is being burned in the cylinder, just like the gasoline. Gasoline carries almost no oxygen in with it and it burns. That's why we have turbos, to provide the air and thus oxygen to burn these fuels! You could run your car on only methanol if you wanted to. There are still some oldschool cars out there running on 100% methanol, I believe Holly still makes a methanol approved carb.
Rich is rich, more H & C than there is O. What am I missing?
02-20-2017, 10:07 AM
#27
TECH Enthusiast
Well the balanced chemical reaction for the combustion of the Methanol is
2 CH3-OH + 3O2 = 2 CO2 + 4 H2O
I'm not sure how that helps though, we have 3 fuels being burned all competing for the same oxygen.
Ethanol is
C2H5-OH + 3 O2 = 2 CO2 + 3 H2O
As for the gasoline it really cant be expressed as such because it is not a pure compound like ethanol or methanol. Combustion data for gasoline is obtained empirically.
Either way not all of any of the 3 fuels is burned, they are all partially combusted. For example if your tuned to 0.80 Lambda, roughly 80 % of the fuel is burned. There is still some free oxygen though even in a mixture this rich, that is why wideband O2 sensors can tell the difference between 10:1 and 11:1, there is still most oxygen present for them to measure, in both cases, just a little more in the 11:1 mixture than the 10:1 mixture. Adding peroxide to the mix would oxidize more of the fuel, but I don't think that would be any different than leaning the mixture through the tuning of the ECU. Having forced induction makes getting more oxygen in there easy enough, just add more boost. Now if we are in outer space where there is no atmosphere, that hydrogen peroxide would come in really handy. But that is getting into rocket science, pun intended.
2 CH3-OH + 3O2 = 2 CO2 + 4 H2O
I'm not sure how that helps though, we have 3 fuels being burned all competing for the same oxygen.
Ethanol is
C2H5-OH + 3 O2 = 2 CO2 + 3 H2O
As for the gasoline it really cant be expressed as such because it is not a pure compound like ethanol or methanol. Combustion data for gasoline is obtained empirically.
Either way not all of any of the 3 fuels is burned, they are all partially combusted. For example if your tuned to 0.80 Lambda, roughly 80 % of the fuel is burned. There is still some free oxygen though even in a mixture this rich, that is why wideband O2 sensors can tell the difference between 10:1 and 11:1, there is still most oxygen present for them to measure, in both cases, just a little more in the 11:1 mixture than the 10:1 mixture. Adding peroxide to the mix would oxidize more of the fuel, but I don't think that would be any different than leaning the mixture through the tuning of the ECU. Having forced induction makes getting more oxygen in there easy enough, just add more boost. Now if we are in outer space where there is no atmosphere, that hydrogen peroxide would come in really handy. But that is getting into rocket science, pun intended.
02-20-2017, 10:47 AM
#28
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Gasoline isn't nearly as effective as water or methanol in cooling, so adding large amounts of gasoline to the mix to try and match the benefits of a much smaller amount of water or methanol is a poor solution.
Water has the highest latent heat of vaporization of all common substances. The only thing that holds a candle to water when it comes to cooling capability is Ammonia.
02-20-2017, 10:49 AM
#29
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So, say we're running straight Methanol and the mixture in the cylinder has more than 2 CH3-OH for every 3 O2... for simplicity let's just add 1 molecule to the equation. 3 CH3-OH + 3O2, wouldn't the exhaust byproduct be 2 CO2 + 4 H2O + CH3OH, where the additional fuel is completely unreacted in the process of combustion?
02-20-2017, 11:03 AM
#30
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Seth, you're forcing this to go south. Your argument seems to be headed towards water/meth is pointless and the running anything more rich that stoic is only needed for cooling.
I'm out.
I'm out.
02-20-2017, 11:12 AM
#31
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Even at stoic, the chances there is perfect combustion are low. This is why you gain power by running 12.5:1 on N/A.
Gasoline isn't nearly as effective as water or methanol in cooling, so adding large amounts of gasoline to the mix to try and match the benefits of a much smaller amount of water or methanol is a poor solution.
Water has the highest latent heat of vaporization of all common substances. The only thing that holds a candle to water when it comes to cooling capability is Ammonia.
Gasoline isn't nearly as effective as water or methanol in cooling, so adding large amounts of gasoline to the mix to try and match the benefits of a much smaller amount of water or methanol is a poor solution.
Water has the highest latent heat of vaporization of all common substances. The only thing that holds a candle to water when it comes to cooling capability is Ammonia.
Yes, latent heat of evaporation is mention worthy. But, how do the different substances react in gaseous form? How much do they expand or how much pressure to they contribute to the power stroke for every unit of thermal energy they absorb? And how do they relate to the other gasses in the combustion chamber? Which gas is doing the most work for the least energy absorbed?
Last edited by SethU; 02-20-2017 at 11:24 AM.
02-20-2017, 11:22 AM
#32
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Not the case at all Joe. I'm all for it. And all for understanding the process as thoroughly as possible. You and Scotty seem very knowledgeable and capable of discussing some of the deeper points. I think you may have read me wrong, stick around.
02-20-2017, 04:22 PM
#33
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So, say we're running straight Methanol and the mixture in the cylinder has more than 2 CH3-OH for every 3 O2... for simplicity let's just add 1 molecule to the equation. 3 CH3-OH + 3O2, wouldn't the exhaust byproduct be 2 CO2 + 4 H2O + CH3OH, where the additional fuel is completely unreacted in the process of combustion?
CH3-OH + O2 = CO + 2 H2O
This is what can happen when the oxygen and the methanol are in a 1:1 ratio as in your example. This is incomplete combustion, where carbon monoxide is produced. There are multiple reactions occurring. In an overly rich situation, only a very small amount of that excess methanol will pass through, and remain unchanged as methanol. If you are so rich most of the methanol will pass through, you are probably so rich the mixture will blow the spark out, and flood.
02-20-2017, 04:31 PM
#36
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word, I'm up on latent heat of evaporating fluids
i guess my more focused question is: what is happening to the water? is it simply carrying heat energy out? or is there more going on?
I would think it would affect the flame front speed---maybe controlling and slowing it---(which is good, a hot turbulent charge can have multiple flame fronts and be a cause of detonation)
but that is my own conjecture. I am just a fabricator who likes to think about stuff.
i guess my more focused question is: what is happening to the water? is it simply carrying heat energy out? or is there more going on?
I would think it would affect the flame front speed---maybe controlling and slowing it---(which is good, a hot turbulent charge can have multiple flame fronts and be a cause of detonation)
but that is my own conjecture. I am just a fabricator who likes to think about stuff.
02-20-2017, 05:14 PM
#37
Lol Im back in science class. I am getting older so this is bringing me back over 30 years...Wait..my hair is full, Im wearing bell bottom jeans again LMAO. I understand that the farther away is a cooling affect and closer is octane boost? Im going to put 14 psi to her and I think octane and some cooling will be the trick? Note to Ron..We had some serious talks on Chevelles about BBC's but this is mad science Lol...KEEP IT COMING I LOVE INFO
02-20-2017, 06:30 PM
#38
thanks bud, please tell that to the engineers at my work---they think we just beat on stuff with sticks like wild gorillas haha
so think makes me think the water is pretty homogeneous in the mixture yes? so its kinda acting like a "spacer" in between the other molecules?
it's been a long time since o-chem so please speak very slowly
The water does this by displacing air and fuel, it doesn't really participate, it is just along for the ride. It also absorbs some of the energy, and reduces EGT. The concentration of reacting components is one of the factors in controlling reaction rate, by adding water we reduce the concentration of the fuel and air in the cylinder.
it's been a long time since o-chem so please speak very slowly
02-20-2017, 07:05 PM
#39
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This is also something that is not that simple, there is more than 1 reaction occurring. In your above hypothetical example where you have 3 methanol, and 3 oxygen reacting. The 2 components are in a 1 to 1 ratio on a molar level. In addition to the equation where we have complete combustion to carbon dioxide and water we also have the following equation :
CH3-OH + O2 = CO + 2 H2O
This is what can happen when the oxygen and the methanol are in a 1:1 ratio as in your example. This is incomplete combustion, where carbon monoxide is produced. There are multiple reactions occurring. In an overly rich situation, only a very small amount of that excess methanol will pass through, and remain unchanged as methanol. If you are so rich most of the methanol will pass through, you are probably so rich the mixture will blow the spark out, and flood.
CH3-OH + O2 = CO + 2 H2O
This is what can happen when the oxygen and the methanol are in a 1:1 ratio as in your example. This is incomplete combustion, where carbon monoxide is produced. There are multiple reactions occurring. In an overly rich situation, only a very small amount of that excess methanol will pass through, and remain unchanged as methanol. If you are so rich most of the methanol will pass through, you are probably so rich the mixture will blow the spark out, and flood.
Referencing a few charts plotting exhaust byproducts to AFR, the CO and HC seem to increase at a near identical rate with increasingly rich AFR, although HC's about 10 x less than CO%.
This is from one of the more interesting reads I've read lately and I'm wondering if you might be able to Speak to it a little. Agree/Disagree/Not the full Story??? (Full write-up link below the qoute)
When hydrocarbons like gasoline combust, the burn process actually happens in multiple stages. First the gasoline molecules are broken up into hydrogen and carbon. The hydrogen combines with oxygen from the air to form H2O (water) and the carbon molecules form CO. This process happens very fast at the front edge of the flame front. The second stage converts CO to CO2. This process is relatively slow and requires water molecules (from the first stage) for completion. If there is no more oxygen available (most of it consumed in the first stage), the second stage can't happen. But about 2/3 of the energy released from the burning of the carbon is released in the second stage.
What caught my eye was the claim that 2/3 of the energy is released in the second stage of combustion where water is required to convert CO to CO2. It doesn't say what role the water molecules play. I'm guessing the water isn't being broken down and contributing any of it's O atoms to the creation of the CO2 molecule. Or does it? Do you happen to know?