Curious how many of you are injecting water only to lower IAT's and to increase the octane? How effective is only water, or is some fraction of methanol required for effective cooling? I have yet to find anywhere in my area that sells methanol, and the lowest washer fluid around here is +32F. I think the most methanol I would use is 50/50. The best I can find online is -25F (around 38% methanol), but I'm not even sure if I can have it shipped to me yet.

Straight water would also be absurdly cheap, I wouldn't feel bad at all about using a bunch of it

 

Water only isnt very popular. 50/50 is about as low as I would go and I run 100% meth myself as do many people on here. If you have a shop that orders VP racing fuels ask them to order some M1 Methanol next time.

 

the higher octane geneerally means resistance to combustion. so.. i guess technically spraying water would do such a thing. note: octane is an actual chemical if memory serves.

spray water DOES work as long as you have a good spray pattern and adequate atomization.

water was also one of the first things used so it is nothing new. was actually stock on a few cars 'in the beginning'.

 

I run -20F from PepBoys, or -30F that I found at a local truckstop. You might try checking out a truckstop. That's the only place that I could find -30F. The methanol helps with the cooling quite a bit. I don't run 50/50. You might also try a mom/pops hardware store. The local one here carries 5-gallon can of straight methanol. A friend of mine does that and mixes his own. It's called McFaddendales. Looks like there are a few in CA.
http://mcfaddendalehardware.com/

 

I'm sure it will help, just not sure how much. Maybe worth a try it in small qty and and see how it does. Eventually as u add more and more, you may need to close the gap up a bit on the plugs. If you try, let us know how this works for you.

 

Got this info a while back.


100% water is good for preventing pre-ignition. It cools the combustion chamber and physical parts helping to eliminate hot spots. It also absorbs some of the peak heat during combustion helping cool everything as well.
Add too much water and you will blow out the flame front causing mis-fires. My basic description is, using 100% water you need a lot of "heat" By heat I mean boost and or compression. Using water on a low compression and moderate boost motor can be tricky.

100% methanol is good for adding real octane numbers and cooling the inlet track. Methanol will evaporate to a lower temperature int eh inlet track than water lowering the effective IAT. (We can argue about wet vs dry bulb temps but that's another subject). Methanol burns cooler and slower than gasoline helping cool the EGT's as well. Many tuners will find it's easier to make quick power on straight methanol, as the greater BTU release, increased octane, lower IAT and EGT all lead to power increases.

Some folks swear by straight water and some straight methanol. I've found it's pretty application specific.

AS for getting and mixing. Many people run 50/50 for the combined attributes of both liquids, and relative ease of procurement. 50/50 can be bought from some of the methanol suppliers. Other folks will research the best windshield wiper fluid they can find in their area. It can be found in 20-50% methanol concentrations. Try to find some with as little dye, and no detergents as possible. I know in CA finding it without detergents is hard.

Remember, if you get tuned for say 30% meth, you can generally go to higher concentrations later without damage, but if you are tuned for 50/50 and run straight water, you will run lean.

Hopefully this helps.

 

Thanks, I had read that too on another site, forgot which one. I guess I was hoping for some real world experience from fellow LS owners.

My SCR is 9.5 and I will be running up to 15 psi. My initial plan is to run dual 7gph-rated nozzles, but with the pump turned up it will probably end up at 20gph total. The highest octane fuel here is 91, so some sort of water/methanol injection will probably be necessary just for safety.

 

Im on a 5.3l with 317 heads (8.6:1) and im on pump gas (93) on a 76mm pushing 15psi @ 21.5 degrees of timing and no knock. I still plan to run 50/50 downthe road when I turn up th eboost to 18-20.

 

I've used water injection quite a bit.

They have their differences. Its mostly a situational difference. Methanol burns, water does not. Methanol evaporates readily at room temperature, water does not.

Water has a very high latent heat of vaporization as well as one of the highest specific heats of all common materials on earth. Therefore, its a much better coolant than methanol inside of the combustion chamber. For ever degree that water rises in temperature, it draws a much greater amount of energy from its surroundings than almost any other common material in existence. Water provides better pre-ignition prevention than methanol. As the air in the cylinder is compressed and the water is heated, it draws heat away from the hot spots in the combustion chamber to prevent detonation. Once the water begins to phase change into a gas, it draws a much greater amount of heat out of the combustion chamber due to a high latent heat of vaporization, thus causing much lower EGTs and possibly even a small power boost from the expanding gas.

Methanol evaporates readily at lower temperatures causing the vaporization effect outside of the combustion chamber. Methanol will cool the air in the intake tract much better than water because it will vaporize quicker. It will also burn in gas form in the combustion chamber.


The main differences are that water will cool much much better than methanol, but you need a much more dense air/fuel mixture for it to have full effect. If the mixture isn't dense enough (not enough dynamic compression) and the water isn't atomized enough, it can cause spark issues or incomplete combustion. Methanol doesn't have this issue.

High boost setups will do better with water only injection. Anything less will benefit from the methanol. The idea behind a 50/50 mix is that you get both intake tract and combustion chamber cooling/detonation prevention with less spark or incomplete burn issues that you might have with water alone. The nozzle used to mist the water is also very important here, as better atomization helps prevent the issues associated with water alone.

This is why lots of the smaller 4-cylinders use water only. They have to push 30 PSI on a street-sized turbo to break 450whp. Water injection trumps methanol injection here.

In a perfect world, water only injection would be ideal. Since its not perfect, adding in methanol is a safer bet, especially since the water/methanol mix won't have issues with things like deposits and buildup like tap water will.

 

A gallon if wiper fluid(assuming its about a 30/70 mix) and about 4 12oz bottles of 'Heet' should give you around a 50/50 mix. Should have it at any autoparts. it's pretty much pure methanol.

 

This. ^^^^^^^^


Any recommendations on which nozzles to use with water injection?

 

is been a few years since I did the math. but i always use 2 bottles of HEET (yellow bottle) per gallon of fluid and im pretty sure that gave a 50/50 mix.

would be nice to see the math again I don't have a break down of the mix of the wiper fluids anymore.

 

HEET is pretty pricey, about $2.50/12oz at my local auto supply, that's about $25/gal.

 

I was going to suggest HEET as well. It is 99.9% methanol. I bought Boost Juice, since I know it is a 50/50 mix and I can't get low temp wiper fluid here. I just add enough HEET to it to bring the mix up to closer to 75% methanol.

Mike

 

Well I guess that's one advantage of living in Canada. You just have to go to your local hardware store or supply store and buy as many 1 gallon jugs as you want. Most often it's labelled "methyl hydrate". Cheap and easy to find, lol.

 

I just run -30F Washer fluid (~30/70) for $2.50 a gallon. I'm not relying on that much methanol to add richness or reduce IATs, however it does lower IATs considerably. Enough for me anyway. I do it mostly for the water (Octane properties) I guess.

At $8+ a gallon +shipping for Boost Juice, I can't justify it, for my setup anyway. Even adding 2 bottles of Heet (at $2.50 a bottle) to a bottle of -30 (at $2.50 a gallon) adds up to nearly $8 a gallon. I'll stick with -20F (and now -30F that I found at the truckstop).

 

I've run 50/50, 66/33, and 100% meth on my car with various boost levels. When 50/50 provided enough octane, it was interesting to note that the car seemed to not knock no matter how much timing I kept giving it. IT just stopped making more power.

At 10.5:1, I had to go to 100% meth when I went from about 13psi to 17psi on that setup. I was using a single m10 nozzle. I had to back timing down pretty low still and ended up adding an m15 to this with 100% meth. More timing and more boost(19psi) was the result with no issues.

Just seems to me you get great protection from water injection, but you get more power and protection with more methanol. I run dual m15's on my current setup.

 

Found a place locally that sells methanol in 5 gal cans for about $40 ($8/gal). That would last while if I mix it 50/50 with water. Don't think I can do any better than this.

 

That's not bad. That comes out to $2.40 a gallon if you mix it at 30%. Same price as windshield washer fluid, no additives. Just have to mix your own. Of course you know exactly what the % is then. Good deal!

 

Check with local fuel supply distributors or circle track races. You can buy a 55 gallon drum for around $180-200. Put up a post on a local car forum that you'd like to divide up the drum if you do not want the entire thing. Or if you go to the local drag races ask any of the alcohol dragsters if you could buy 5 gallons or so off them.