Its partly the reason we use water/alky injection.. since you can run pretty close to a race gas map on 93 octane, then switch to a regular map if you don't need it..

 

To your point...

Here's latent heat of vaporization for each:
Water: 500 BTU
Alcohol: 470 BTU
Gasoline: 135 BTU

Higher is betterer.

I don't have personal experience but I don't think alcohol is necessary unless you need to enrichen the fuel mixture. I would think that if you did lean out the fuel you'd have to be precise about your alky to H20 ratio.

 

I Agree... Usually pure (distilled) water isn't used simply because it freezes in the winter, most people use washer fluid which has a small amount of alcohol and a few additives that are harmless to the engine.

Pure alcohol is never used... it has other problems such as it can degrade the components its sitting in..

Its usually 15-35% alcohol to water mixture.. (hence why washer fluid works)

 

Well, it seems like with some tuning work, this will be a huge bang for the buck mod, and pretty safe. Does anyone have hard numbers, or at least an educated guess, as to the kind of statistics one could see on a stock turbo?

I realize that's largely dependant on what else is on the car, but for simplicity's sake, let's say the Evo is making 300 whp on 93 octane. Injected with alcohol, how much more could you pull out of the car, with stock internals?

 

Alcohol isn't going to add much in the way of power (We've all been running gas with around 10% alcohol content for the past few years anyway) in fact, if you ran your car on pure alcohol, you'd likely be producing less horsepower than on gasoline.. The difference is its combustion properties (high octane rating) means you can run very high boost (assuming your limitations arent engine related) and very aggressive timing (due to its slow burn rate)

The problem is, due to its ability to absorb alot of heat before vaporizing (hence lowering combustion temps) starting an engine running on alcohol is very difficult when its cold (hence why very few of us can or will run pure Ethanol/methanol on the street)

Obviously this is an unrelated example, but hopefully it explains why the AFR's won't matter much, its likely you'd run a little leaner simply because of the water vapor or alcohol is displacing the air a little..

 

Does anyone have any experience with the DerekDevises alky injection system on stock ECU? Otherwise, this seems to be the next best alternative and I'm strongly considering it

 

David,
Is your kit made by smc? If not who?

 

Im thinking, could this possibly eliminate the need for a upgraded intercooler.

 

I dont think so. The WI kit is after the IC and not post so you still could run into heatsoaking the IC

Chris

 

Well, technically it could reduce the need for an upgraded intercooler, but upgrading the intercooler also means less restriction and more air into the engine, which also offers a power gain.

 

If you guy's want some really technical water/injection info go on the Supraforums and do a search for the user Anarky. Lot's of posts about difference Alcohol mixtures and which types provide the best gains. He's building a Supra now that will run without an intercooler on straight methanol on WOT; and off-boost & idle on Propane without a throttle.

 

Actually, WI can replace an intercooler altogether, but it wouldn't be very practical and you would need a complex setup that would monitor blocked jets, etc.

I think I remember reading that years and years ago an OEM was contemplating using WI on a car in place of an intercooler, but if the owner forgot to refill the water tank, there would be too many problems. I forgot who it was, though.

But the point is, yes, WI does the same exact thing that intercoolers do, but as MalibuJack pointed out, depending on your airflow levels, you always want the highest flowing and lowest pressure drop IC.

Eric

 

Hi, that's a good point, but overall, I think the whole system needs to be optimised to run alcohol.

In fact I remember when I was in Brazil that about 50% of the cars did run off of alcohol, and for that matter, had a bugger of a time starting in weather less than about 50degF. As newer cars came out (like MY 97+) they started using a gas start and alcohol run, when the engine came upto temp. Overall I thought alcohol fueled cars to be really neat. They had kind of an acrid smell, but most people (who hotrodded them) really pulled a lot of power out.

If my understanding doesn't fail me, I think they had a different injection requirements, different plenum, different cams, and different timing. All these variables are perfectly 'reasonable' to change in an EVO, but it could get a little costly a little quickly.

jcnel.

P.S. Brazil is where I obtained my love for Escort XR3s. Neat platform .

j.

 

Yeah, I've always wanted to build and run a car that ran completely off ethanol.. any gas car can be converted, but its pretty costly.. However this waterinjection system really isn't intended to run off the alcohol, just use the water/alcohol to reduce the intake charge temp, and absorb heat to prevent detonation and allow more aggressive timing.. more timing means you can put more air and fuel into the cylinder and expect it to be able to burn the mixture and the gasses will begin to exhert pressure against the piston at or after top dead center..

 

Where's David? I need more info. I've always been against adding a WI system to a high strung daily driver because you are adding one more system that has the potental for failure... however, with more and more safety features being added to these systems, I becoming interested.