ScottyBG

That's how I believe it to be true. It hinders the other molecules collisions, because it is in the way, so the hydrocarbon, and oxygen molecules can't get to one another to react so quickly. The nitrogen present in the air also does this, as well as the carbon dioxide present after some of the mixture has already started to combust, but we're getting into a whole 'nother story there too.

Modchevelle

iTrader: (9)

Now that my head is spinning and that is Ok. Putting the nozzle before the bov will just act as a cooling effect not a octane boost?

ScottyBG

I agree with that article, there are no gross misstatements in it IMO. However it is written to keep it simple, so you don't need a PhD to understand it, which honestly some of this does get into very complex reaction kinetics, especially when you get such complex fuels combusting. Believe it or not, gasoline is common, but is a far more complex fuel than any of these pure substances like methanol or ethanol.

Here is what I think it fails to help people understand:

Normally in an internal combustion engine the limiting factor is air, not fuel. So the article looked at it from a fuel stand point and having too much of it. Think of it the other way around, you only have so much air and want to consume as much of it as possible. That is why being richer than stoic actually makes more power than stoic. If you looked at it purely from the point of view of wanting to have the exact correct amount of fuel to get all of the carbon available in it, through the first and second stage, the max power mixture would be 14.7ish. That way you wouldn't be wasting oxygen on the first step, that could be used in the second step if you had just the correct amount of fuel. But we know stoic is not best power mixture. Unless you go to the rich side you can not consume all the air with fuel.

The second thing they fail to mention is that a significant portion of the energy comes from forming the water, not just the carbon monoxide, and carbon dioxide. They fail to mention this portion in their discussion. I'm sitting at the bar in a Texas Roadhouse swilling a Bud light right now, and don't have access, or care to look at any thermodynamic tables right now, but IIRC the formation of the water creates more of the energy, than the formation of the CO2. I could be wrong on this, but I know it is a significant portion. Thus the interest in using hydrogen for fuel, in fuel cells.

And the function of the water in the conversion of CO to CO2 it is just a catalyst, it can happen at high temperature without water present as long as there is free oxygen present. This however would be a much slower reaction, and there is always some water present during combustion to promote this, so it is kind of a moot point. It doesn't take much water to catalyze this reaction, just the moisture normally found in the air would be enough.

I hope this helps more, I kind of feel like we hijacked this thread talking about combustion, more than we did methanol injection. I actually did my thesis on this type of stuff working with a professor that was jointly employed by the university and Shell, back in '91 and '92. Believe it or not we were looking at adding ethanol to gasoline back then, and all its effects on combustion, engines and the environmental impact. In 2006 that became the reality.

truckdoug

iTrader: (25)

yes we strayed, but I learned something new and thats pretty cool. thanks for all the info

SethU

Sorry about the slight derail Modchevelle.

You'll still get both benefits.

The concern of the proximity and placement of the nozzle to the BOV is when injecting pure methanol or any concentration with greater than 50% methanol. At less than 50%, the mixture is not flammable in open air.

Obviously, you don't want to have a fire hazard every time the BOV vents.

Not to say that if you did inject pure meth, that it would or wouldn't be "rich" enough to actually ignite if it blew out the BOV (that's another conversation).

It's just a safety precaution.

ScottyBG

Actually the Tuning School is doing a video series on meth and water injection on their YouTube channel right now. They did the first phase using just distilled water. They got like a 3 hp and 14 lbs ft torque boost from using water alone, basically the cooling effect of the water. I believe they are going to test the 50/50 next. Previously they tested several fuels like MS109, C16, and ethanol blends. They only tested 40% ethanol though because they are using a Gen 5 engine with direct injection, and it doesn't have enough injector to go any higher. I'm waiting to see the results of the 50/50 and I hope they test 100% methanol.

Modchevelle

iTrader: (9)

Lsxmalibu has the meth going into throttle body which I like but I dont know where his IAT sensor is. I have a stock ring gaped motor so is octane or cooling more important at 14 psi?

ScottyBG

Well that is after the iat sensor for sure. That's not a bad idea IMO. That way your not going to get it soaked. I think as long as you tune the car with it there you will be fine. If you were to move it later to back before the iat sensor you should retune it. You will compensate for the additional fueling and the temperature drop from the injected solution through your VE and boost enrichment table so that your wide band reading reflects the fueling your hoping to achieve. Basically you will be pulling a little fuel to compensate for whatever fueling the solution contributes. Or adding less additional fuel under boost, compared to what you would be adding without this contribution, however you want to see it.

truckdoug

iTrader: (25)

hey so i'm getting all my ducks in row to dyno soon. first time meth user (lol)

will likely spray 70/30 mix

my plan is to not just rely on sensor data but pull plugs and see what the engine like the old fashioned way. i'll bring a couple sets of tr6's

here's the question of the day....what does water/meth do as far as reading your plugs...same process?

Modchevelle

iTrader: (9)

I thought meth had to go before the IAT so computer can see intake temp and adjust? Im using the Holley HP computer. Im not sure if I like the idea before the BOV because the turbo is still pushing when throttle blade is closed quick.

3 window

iTrader: (1)

IMHO being on OEM pistons, I'd go for cooling rather than octane. Seems even some pump gas guys go a little rich in order to use the additional fuel for cooling purposes on the SBEs. Again, these are just things I've come across discussing this topic with some other people.

ScottyBG

There is often variation in what the intake temperature of the air is as it enters the intake valve to the cylinder, vs what the temperature of the air is as it passes the IAT. Take for example on a cold day on an NA factory motor, air passes by the IAT at roughly the outside temperature. By the time the air makes it through the warm throttle body, which has engine coolant circulating through it at about 200F, through the intake manifold, which is sitting on top of a hot engine, down the intake runner of the hot cylinder head, and over an intake valve about 400F it is quite a bit warmer than when it passed the IAT sensor. This temperature change is accounted for in the tune because the air is warmed a relatively consistent amount. Basically the VE table is tuned under these conditions to be correct. There is a table based upon ECT that can be used to modify this if necessary. The whole reason mass air systems exist is because of this temperature change that occurs in the engine, mass air doesn't have to worry about this.

In your case you will have a similar thing happening, a change in temperature of the intake charge after the IAT. So as long as you are spraying a consistent mixture ratio, like 50/50 or 70/30 or such, and a consistent amount, at a given boost level, your tuning will take care of this IAT change that happens after the IAT sensor, just like in the example I gave above on the factory motor. You will want to tune your VE table while spraying the meth/water or 100% meth, whatever you chose to do. If you decide to change pump pressure, mixture ratio or nozzle sizes you should adjust your tune afterwards. If you spray more meth you will need to reduce fueling, and can increase timing a little, if you spray less meth you will need to add more fuel, and pull a little timing.

I'm confident you can tune around injecting it at the throttle body.

JoeNova

Overthinking it. Way too much.

You can spray after the IAT and adjust your tune so that its where it needs to be when meth is spraying. I personally avoid this method. There will be no adjustments made and no fail safes if the meth doesn't work.

Spray before the IAT and adjust your tune so that its where it needs to be when meth is spraying. Don't worry about how much it adjusts fuel or anything else. Just spray, and check the tune. Adjust the VE table so your AFR is where it should be for a fully working system. Don't pay any attention to what % of that adjustment is IAT, etc. Its irrelevant. Use the IAT as a fail safe. Your IATs will be very low with meth on 70-90* in most cases. If your bottle runs out or the pump fails, they will be much higher than normal. Have it pull timing if IATs are above 120-130. Its a win/win.

You're overthinking the throttle body portion as well. People are their own worst enemy. Worst case, an ounce stays in your intercooler piping and evaporates off in the next few seconds.

RICE ETR

iTrader: (3)

This thread is great, and I appreciate all of the knowledge here!
Just a quick question, if spraying before the IAT and the meth/water fails, will the sensor react fast enough to save my engine? I am running MS3 Goldbox and a typhoon thread in sensor.
I have always run my injection after my IAT for various (unfounded) reasons, but would like to try before this time around.
Thanks again

JoeNova

Your engine isn't going to magically blow the instant meth fails. You'll have a cushion as long as you weren't on the ragged edge even with meth.

The IAT should be able to climb from 90 to 120 without meth in ~1 second, maybe less depending on how hot IATs really are.

RICE ETR

iTrader: (3)

I don't plan on running on the ragged edge but I am definitely intrigued with using this as a way to check for injection function.
Thanks for the response!

Modchevelle

iTrader: (9)

Sounds like before the IAT for me since I have stock pistons and gaps. Cooler the better?
I cant tune for nothing..I have to have a guy look at my tune on the net

69-chvl

iTrader: (11)

Mod is running wot closed-loop so he doesn't have to alter his tune I believe.

Modchevelle

iTrader: (9)

Hey 69...How the hell are you. Long time. Seems like some old chevelle.com buddies are chiming in. Yes im in closed loop. Hey guys..this is the guy who got me running since I dont know a MAF to a knock sensor is. I think 69 chvl is a great person for helping me out

forcd ind

iTrader: (7)

What Joe says does make sense, tune w/o spray, then tune with spray and let the IAT's adjust, if it fails it would pervert back to the safe pre meth tune.
I just added a flex fuel sensor, might play with that.