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Water/Alcohol injection adds octane?

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vinh766

15+ Year Contributor
137
2
May 20, 2003
SoCal - ATL - PHX, California
i will be moving from an area of 93 octane (east coast) to 91 octane (west coast), i've heard that alky injection adds octane, i was wondering if i went w/ a 50/50 mix, would i be able to compensate for the octane loss? or even more? thanks.
 
From what I've researched on Water Injection it should do the trick... and then some. It doesn't exactly "raise the octane" of the gas... but it has the same effect. The Water Injection cools the intake air allowing more air/fuel to enter the engine... and thus more boost. I believe a higher octane gas allows for more boost due to the fact that it burns more efficiently.... which means less heat... which equals less knock... etc.

On top of the cooling effect, Water injection will clean the entire intake and engine internals (combustion buildup)... helping to keep those knock levels down.

On a totally random note... the rims in your profile are Schweet! The paint looks like a gun metal color. Did you just get that done at a shop... or did you do it yourself?
 
that is correct. it does not ADD octane, but the effect is as if you were running higher octane fuel. as much as 6 points. so, 91 octane could be like 97. to be safe, 4 points, which will be in effect 95. a lot of the extra fuel needed at boost is for cooling. and you dont need the alcohol, plain water will do very well. distilled, of course. i have found that a lot of the blue windshield washer fluid does NOT use distilled water, and it will clog up your nozzles. make sure you use a very good filter on the feed side.
 
thanks for the replies. i am planning on doing the DIY kits from so many of the writeups. i plan on going w/ the 60psi shurflo pump and then tuning it to run 100psi and getting the rest of the parts from napa, and nozzles and stuff like that from mcmaster.com. i've read also that it isn't neccessary to use a filter anymore, what do u guys think of that? and if so, what if i still run the winshield washer fluid, and use a filter, u guys think that would work on the non-distilled 50% of the water in there? if not, then im gonna search for that distilled mix windshield washer fluid and buy like kegs of it :thumb: . im really excited about getting this setup, i'll let you guys know how it goes once i accomplish this next mod.

and about my rims, i did those myself, sorta took a while to strip the old paint, but after u see the polished silver underneather, its worth every minute of it. i strayed it w/ a gunmetal rim paint, and there was a bonus that i didn't account for, it has pearl in it too! it looks badass in person (when the car is clean) and i plan on painting the bottom trim (since its a close match to the gunmetal) the same color/paint as i did w/ the rims, so it has the pearl in it too. and i finished everything off w/ a couple coats of clear coat. looks a lot nicer in person.
 
Yeah, the water/alchy lowers the intake charge temperature. Higher octane gas has better resitance to preignition under High temp and High pressure. By lowering the intake air temperature and absorbing heat durring cumbustion you remove a major factor that creates knock(heat), this allows you to run lower grade gasoline and higher boost since you no longer need such a high octane to keep the knocking away.

This gives the effect that is often refered to as, and precived as effectivly boosting the octane. That isn't to say water injection and high octane gasoline isn't beneficial.\

This is how I understand the effect.
 
do i still need a filter though?
 
One thing I think should be taken into account is that water does, through a cooling effect, help keep knock levels down. It would be a good idea to run a mixture of water and alcy b/c alcohol of some sort (like methanol - which is the best form to use) has an octane level of 140 to 160 and if added to an a/f ratio actually CAN raise octane levels. If you add only 10% pure methanol to a mixture you will see a raise of about 5 points of octane. So 91 can be raised to 96 octane! That's awsome. Also, the use of Methanol enables a power increase to be obtained by the simple act of using a higher compression ratio and in fact with 10% the ratio can be increased by 1.5. And what's sweet about us and our turbo cars is we just raise the boost to see higher effective compression ratios.

Now, I'm not saying everyone should go out and get a hardcore setup for alcy injection, I'm just trying to show that by using a mixture of the two in the injection you can really take advantage of both worlds. You will be able to keep knock under control by keeping the intake charge and combustion chambers cool and by actually raising the octane level of the fuel entering the engine.

Kent
 
thanks so much for all the info, the best part is, i see that two of you are from arizona, i will be moving there in 2 week, and i won't be putting on this setup til i get there, so hopefully i can still get personal help from u guys in that area, and if my car blows up, i know who to go to also. LOL, jk guys. thanks a bunch though, im now gonna start buying parts to put this kit together from this list:

http://www.turbomirage.com/water3.html

please let me know if something looks out of place, or any other suggestions i should add. TIA
 
oh, one more thing, im a 2g, and i have a data logger but i have no way of knowing what my injector duty cycles are. i have maxed out 550's already due to the cold winter weather over here, and so i went ahead and got some 720's (hopefully to supply fuel to a bigger future turbo), and i've read the formula to figure out what size nozzle would be appropiete, but im a 2g, and my logger does read duty cycle %. so i still have no idea what my duty cycle % are. please let me know what i should do.
 
One thing, although many people tend to preach water, Alcohol does have octane properties. To be specific I believe methanol, which is the main component of denatured alcohol has an octane rating of 124, but with the mix of kits Buschur has stated that running alcohol injection is better or as equal to 110 octane race gas. I know a lot of people love the water route, but I went with alcohol and couldn't be happier. He also used this to put down 400 hp with his Evo and pump gas.

Edit: Just for reference this is the kit I have. www.smcenterprises.com
 
Hey,
Just buy a kit from here. You tell them your estimate power output and they calculate the "right" size nozzle. It sounds a little crazy but a lot of DSM guys are very successful with these kits. I would recommend the "Deluxe single stage kit" ( http://www.coolingmist.com/detail.aspx?pid=02 ) because it comes with the higher pressure pump and an adjustible boost sensor.

Kent
 
vinh766 said:
oh, one more thing, im a 2g, and i have a data logger but i have no way of knowing what my injector duty cycles are. i have maxed out 550's already due to the cold winter weather over here, and so i went ahead and got some 720's (hopefully to supply fuel to a bigger future turbo), and i've read the formula to figure out what size nozzle would be appropiete, but im a 2g, and my logger does read duty cycle %. so i still have no idea what my duty cycle % are. please let me know what i should do.
I'm pretty sure that when you are calculating nozzle size for your system, that you use the "Max duty Cycle" that you want to allow the system to reach. I believe 85% is recommended but you can search some more on that. I use the following link as one of my references to learn more about what kind of a system I'm looking for, but I can't attest to how accurate the info is. Here ya go.
Well you're coming to AZ soon eh? Great timing... right at the beginning of summer! I've heard some great stories from a honda kid about the heat rising off of the asfault.... straight to the FMIC making it pretty much useless. Until you have Water injection, make sure to keep the boost down... or at least monitored... and make sure the AC works!

-Turblown
 
Turblown said:
I believe a higher octane gas allows for more boost due to the fact that it burns more efficiently.... which means less heat... which equals less knock... etc.
Just wanted to clear this up. It's not because it burns more efficiently, it's because it is more resistant to burning. A higher octance gas will take more compression or heat to burn than a lower octance gas.
 
i am currently running 720 cc injectors, i was wondering, since i have the sufficent fuel upgrades, do u think i would be able to run 20psi on 91 octane? without a dought i will be tuning for it, but i just wanted to know ahead of time, or if anyone was running the same setup. im running it on a big 16g with a fmic. thanks.
 
vinh766 said:
i am currently running 720 cc injectors, i was wondering, since i have the sufficent fuel upgrades, do u think i would be able to run 20psi on 91 octane? without a dought i will be tuning for it, but i just wanted to know ahead of time, or if anyone was running the same setup. im running it on a big 16g with a fmic. thanks.


One thing you have to watch out for here in AZ is heat. Intake temps get high, IC's heat soak fast and detonation/knock becomes more and more of a threat. If you plan on running that amout of boost only only 91 oct you're probably going to want to use some kind of injection. Like I said before water deals with heat and alcy deals with oct. I would say use should at least run water injection, if not a 50/50 mix injection to help you in both ways.

Kent
 
dsmpride said:
One thing you have to watch out for here in AZ is heat. Intake temps get high, IC's heat soak fast and detonation/knock becomes more and more of a threat. If you plan on running that amout of boost only only 91 oct you're probably going to want to use some kind of injection. Like I said before water deals with heat and alcy deals with oct. I would say use should at least run water injection, if not a 50/50 mix injection to help you in both ways.

Kent
Alcohol has cooling properties also though.

Alcohol sprayed directly into the charged air stream has a substantial cooling effect and acts kind of like an inter-cooler. Alcohol’s cooling ability reduces detonation and allows higher boost levels to be run with low octane fuel. Cylinder temperatures can drop as much as 300 degrees. Alcohol injection may be added to your recipe at any point as it works well from a stocker to a full racer.
 
I'm not trying to say alchy injection is bad or anything. My friend's '89 TTA has it and the damn thing is a beast...untuned. But the research that I've done and the experience that I have says that if are experiencing knock due to a thermal issue (like we commonly have out here in AZ) go with water since its sole purpose in an injection is to reduce heat. And if you are just having an octane issues, like all of us do, go with the alcohol since it actually is a cumbustable fuel that has a high octane rating. Or you could get the best of both worlds and run a 50/50 mix that will be successful at redusing knock despite the reason.

Kent
 
dsmpride said:
I'm not trying to say alchy injection is bad or anything. My friend's '89 TTA has it and the damn thing is a beast...untuned. But the research that I've done and the experience that I have says that if are experiencing knock due to a thermal issue (like we commonly have out here in AZ) go with water since its sole purpose in an injection is to reduce heat. And if you are just having an octane issues, like all of us do, go with the alcohol since it actually is a cumbustable fuel that has a high octane rating. Or you could get the best of both worlds and run a 50/50 mix that will be successful at redusing knock despite the reason.

Kent
I have four TTA's I know all about it. :D I first had the kit for the TTA and put it on my Talon to see what would happen. I understand your theory, behind water and I am not saying it isn't sound, just that alcohol will also cool and add protection against knock/detonation with increased boost so it is another option. If water is going to be best for the temps out in AZ although I have had no problems running it in 90* weather (granted we have 93 octane fuel and I have a fmic, but on the subject of thermal heat reduction). It could still be an option to use the alky in any case. 300* drop in cylinder temp is quite significant. But if you have first hand experience in AZ then your advice is good. :talon:
 
what if i run 100% alchohol, would that not help out w/ my thermo problems much? i think im going to be running 50/50, and on my california (hometown) trips, im gonna run 100% methonal, just for kicks and higher boost :thumb: if anyone thinks i should do otherwise, please say it now or forever hold ur peace :)
 
Where can you get the alcohol to put in the mixture. I've been considering one of these kits in the future but i don't want to get into it if i can't easily replenish everything.

Btw, I'm east coast born and raised, so i thought everyone had access to up to 95 octane gas. Can you only get 91 out west?
 
You can purchase Denatured Alcohol from places like Home Depot. Yeah the more out west you get, generally, the octane goes down. I'm in Missouri and we used to have 96 back in the day but now it's getting harder and harder to find 93. Theres pretty much only one chain that every location has 93, Kum & Go. Haha
 
illeagle_talon said:
You can purchase Denatured Alcohol from places like Home Depot. Yeah the more out west you get, generally, the octane goes down. I'm in Missouri and we used to have 96 back in the day but now it's getting harder and harder to find 93. Theres pretty much only one chain that every location has 93, Kum & Go. Haha
Yes, any DIY store usually has it Lowes, Home Depot, around 7-9.00 dollars a gallon, and remember 1oz/1gal of uplon lubricant has to be mixed. Now methanol is cheaper at 2-5.00 dollars a gallon and can be found at race fuel distributors, with that you have to add again 1oz/1gal of Klotz fuel lube to the mix.
 
97TSIAWD said:
I have four TTA's

You are my hero...by the way what is this that you are talking about running fuel lube with the meth?

Kent
 
dsmpride said:
You are my hero...by the way what is this that you are talking about running fuel lube with the meth?

Kent
Because of the corrosiveness to metal parts, ie pumps, injectors, lines the creator of my kit instructed me to use Klotz fuel lubricant to decelerate any type of wear, so there should be no problems.
 
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