School Me On Meth Install
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
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?
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?
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
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?
Rich is rich, more H & C than there is O. What am I missing?
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.
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.
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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.
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; Feb 20, 2017 at 11:24 AM.
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.
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.
it's been a long time since o-chem so please speak very slowly
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)
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?









