water alcohol injection mixtures

[91-gsx]

hey i wanted to get a water/alcohol injection kit from ebay that has a 150psi pump as opposed to the coolingmist ones that have a 100psi pump, plus the ebay one cost a little less or about the same. what i was really wondering is what type of mixtures do people run, like what kind of alcohol to water. i do not know what kind of alcohol they use for their mixtures, can i use rubbing alcohol becuase it is 91% alcohol and 9% water?
please help me because i am really looking into getting one.
thanks

 

[Defiant]

Straight rubbing alcohol may be rough on some of the rubberish parts of the system, but it's best to check with the actual pump (the expensive part) manufacturer for details on that. You'll probably find in your researching that the final answer is that the amount of alcohol doesn't much matter, unless you're in areas where the water might freeze. Using something flammable in a water injection system doesn't really make a measurable difference.

 

[91-gsx]

o so it is the water that makes the difference, not the alcohol, i thought it had to be a 50/50 mixture? so the alcohol is there just to keep the water from freezing?
if anybody has a water/alcohol injection kit plz give me feedback on it and tell me what type of mixture you run.
thanks

 

[98spydert]

Straight rubbing alcohol may be rough on some of the rubberish parts of the system, but it's best to check with the actual pump (the expensive part) manufacturer for details on that. You'll probably find in your researching that the final answer is that the amount of alcohol doesn't much matter, unless you're in areas where the water might freeze. Using something flammable in a water injection system doesn't really make a measurable difference.

Sure, the specific heat of water is much higher than methonal or denatured alcohol but it's all about OCTANE not cooling. I don't run 24psi, ~12:1 AFR, and 20* timing on 91 octane because of cooler intake temps

50% Denatured Alcohol works great for me right now but I'm only using it because I don't have a local source for methonal. Most people who are getting really good results are running 70%-80% methanol and distilled water. Get a few different jets and start small. Or get the aqua mist HSV set up if you're willing to pay a little more.

When you order from BE COOL on e-bay, don't let him figure out your nozzle size for you. Find out what you need here and order a few different sizes from him with your package.

 

[91-gsx]

what do you mean denatured alcohol? and i am still wondering if i could use rubbing alcohol instead of methanol?
thanks so far

 

[red95tsi]

Just make sure you use DISTILLED water and not tap or spring water.

 

[ken inn]

what do you mean denatured alcohol? and i am still wondering if i could use rubbing alcohol instead of methanol?
thanks so far

dont use rubbing alcohol. use denatured. you can get it at home depot, or any paint store. denatured is mainly methanol, but it has acetone and some other additives in it, to make it poison. if you drink it, you go blind. methanol is grain alcohol, like in booze. if it is drinkable, they tax it like booze, and it would be killer expensive. so, they mix in stuff to make it NOT drinkable. straight distilled water will have the effect of raising octane about 4 points.

 

[doug]

it's all about OCTANE not cooling.

You sure about that? I was under the impression that the main benefit was the cooling of the intake charge, which minimizes knock.

 

[gixrman]

Its not so much about the cooling to a point, because yes water has 4x the heat absorsion its the way water slows down the flame front to help prevent knock. Water will help you get a denser air charge on those hot summer days. If you want to up the octane add Toluene, or go Propane injection. Many people have had good success with just straight water injection or the smurf piss.

 

[98spydert]

Its not so much about the cooling to a point, because yes water has 4x the heat absorsion its the way water slows down the flame front to help prevent knock. Water will help you get a denser air charge on those hot summer days. If you want to up the octane add Toluene, or go Propane injection. Many people have had good success with just straight water injection or the smurf piss.

Do a real world test then report back with a follow up. There will be NO benefit of running 100% water over a mixture of methanol/ethanol and water. I know because I tried both after reading arguments for both sides. The physics say yes, water evaporating will absorb more heat. I don't have an air intake temp probe in the manifold so I couldn't tell you if that's true in water injection. I can tell you that 100% distilled water doesn't produce anywhere near the results 50%/50% distilled/ethanol does. Methanol has an octane rating of 117, Ethanol of 116 IIRC. I run a 600cc nozzle and 50% ethanol and end up being able to run boost, timing, and an AFR similar to that using 100oct or more.

If you've tried each and came out with water being the better of the two, I believe you. If you're just passing along information you read on the net, you'll be surprised when you actually try it.

Propane is definitely an option but more expensive. Toluene eats fuel lines and seals (even with the proper lubricating agent sometimes).


PS, slowing down the flame front is not a good thing, I don't know where you came up with that. Slower combustion means less output means less twisting force at the crank, how is that a good thing? A slower flame front wouldn't thwart pre-ignition anyways.

 

[Defiant]

Sure, the specific heat of water is much higher than methonal or denatured alcohol but it's all about OCTANE not cooling. I don't run 24psi, ~12:1 AFR, and 20* timing on 91 octane because of cooler intake temps

I've read the claims about the "octane boost", and I'm very skeptical of it. For one thing, what's your WI usage compared to gasoline? Are you going through quantities of alcohol that approximate the amount of gas you're burning? If not, the "octane" won't be in sufficient quantity to matter.
It's also not about cooling the intake charge. The exposure time won't allow for much transfer, and again, the quantities don't bear out the phenomenon.
Water injection is about the chemistry of combustion, and the water's stabilizing effect on it. Not so much a slowing as a controlling effect. There's some thought of the dissociation of the atoms of hydrogen and oxygen in the combustion process, but that also is unlikely as that doesn't begin happening until around 4000°F, and even if it were to go on inside a cylinder, both the hydrogen and oxygen would recombine back into water so immediately that the effect probably couldn't be measured.
However, the "why" of WI, with or without other additives, is not nearly so important as the mere fact that it does do good things to engines, combustion, and cylinder cleanliness.

 

[QuienesTuPapa]

Turbo magazine did an interesting article on alcohol injection in their august issue. It might be helpful

 

[98spydert]

It's also not about cooling the intake charge. The exposure time won't allow for much transfer, and again, the quantities don't bear out the phenomenon.

The cooling effect isn't about having cool water next to hot air and having some sort of heat exchange happening. It's about the amount of latent heat the H20 absorbs while converting from a liquid form to a gas. The heat absorption is instant with the evaporation, unlike a heat transfer, which does take at least some exposure time.

 

[jlo]

You could always just use winshield washer fluid. It's like 50% denatured alcohol, 49% water and 1% blue dye. I know from experience that it does work very well.

 

[98spydert]

You could always just use winshield washer fluid. It's like 50% denatured alcohol, 49% water and 1% blue dye. I know from experience that it does work very well.

It's actually methanol, not ethanol (denatured). Take a look at the side of the bottle.

A lot of people seem to think that stuff is hit and miss. You never know what you're really getting in it. After all, it's not made for combustion, it's made to not freeze and wash bugs away I wouldn't know first hand though, I've never tried it. After seeing the blue dye caked onto the inside of my water reservoir, lines, and anything else it touched, I don't want that in my WI system and especially not in my engine. Just my opinion though.