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Discussion Starter · #1 ·
what does every1 here think about alcohol injection? ive been leaning towards it for the track think its worht it my friend owns a shop and he makes the kits but i wanna get some other opinions first. thanks
 

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I think alcohol injection is awesome! A mustang guy on corral.net sold me on the idea when I had my s/c 91LX, but never got around to doing it, the guy's name is edward clark (modular guy).

I hear snow performance has some alright kits. Also I have seen a vid of a 900 horsepower s/c viper using alchy injection to cool the intake charge.

I say go for it, but be careful! Make sure the mixture is correct and also that you are not using the alchy in excess as it could (what I've heard) wash the cylinder walls clean dry if you are spraying toooooooo much which would be bad :-?
 

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Well, I have an alcohol injection system on my truck...
In fact, its at JLP right now getting tuned for it.

Basically, as long as the injection system is working properly, it can only do good things.
By injecting a fine spray of alcohol into the inlet, you not only cool the charge air but, you also raise the effective octane of the fuel... something that's very important for us CA guys running 91 octane gas.

Its improved quite a bit with progressive controllers.
The only thing you have to worry about is a failure in the system. If you spray too much alchy you'll know it, as the vehicle will fall down on its face. It's pretty safe - just as if you were tuning and dumped too much fuel in. If the unit fails, like if you get an injector clogged or the pump failed, then the better kits activate a boost bypass to dump boost so it protects you as well as light up the controller panel in the passenger cabin. I don't know of any electronic boost controllers/bypass units for an L or whether it can work on our vehicles.

On your street tune, if you don't change anything and you dial the kit in right, it can serve as a great way to keep detonation away.
On your race tune, you can run 20 degrees of timing on 93 octane gas just like you were running 100 octane gas.

camcojb is running the SMC kit and has quite a bit of experience with it. I'm sure he'll chime in here soon.
 

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Discussion Starter · #4 ·
thanks for the input my friend makes the kits and has them running on a couple l's and and also on a 26 pound boosted harley davidson edition.
 

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BoostinSvt954 said:
thanks for the input my friend makes the kits and has them running on a couple l's and and also on a 26 pound boosted harley davidson edition.
Cool... yeah there are a number of how-to's you can find online as to how to fabricate your own kit.
The Buick guys have been doing that for a while now.

Here's some additional information about the theory of water/alchy injection:

Water injection relies on the fact that it takes much more energy to raise the temperature of water than it does to lower the temperature of air. The specific heat of a substance is a measure of the amount of energy (kJ) required to increase the temperature of a certain amount of it (kg) by a certain temperature (° C). The specific heat of water is 4.184 kJ/kg ° C. This means that it takes 4.184 kJ of energy to raise one kg of water 1° C in teperature. The specific heat of water is more than four times that of air, which ranges from 1.00 kJ/kg ° C to 1.05 kJ/kg ° C, for the temperatures we're concerned with.

Water injection is dependent upon the relative humidity in the atmosphere. Lower humidity will increase the effectiveness of water injection.

Advantages to Water/Alcohol Injection
Suppressing Engine Knock. Water injection works to suppress engine knock in several ways. First, the water (and alcohol) reduces the temperature of the compressed air. When the exhaust gases are expelled from the combustion chamber, the cylinder, piston, and valve surfaces are at a very high temperature. The water entering the cylinder with the compressed air will work to cool these surfaces and any hot spots which might exist. It is in these hot spots that predetonation would typically occur. As the air is compressed in the cylinder, the water serves to reduce air to fuel contact, reducing the likelihood of auto-detonation. Lastly, if any alcohol is used, it serves to increase the octane of the fuel.
Increasing Intake Air Density. As previously mentioned, the water serves to decrease the temperature of the charged air. Since water injection presents no additional flow restriction, this reduction in temperature can only be accompanied by in increase in air density. Also, when the water cools the metal surfaces in the combustion chamber during the intake stroke, this allows more air to enter the cylinder - effectively increasing the volumetric efficiency of the engine.

How Much Water and Alcohol?
Water to Alcohol Ratio. A 50/50 water/alcohol mix is recommended as the minimum, with 70/30 being quite common. In fact, many people use filtered windshield wiper fluid without any modification for a very cheap solution. For our analysis, we'll assume a 70/30 mix, which will have a specific heat of 3.66 kJ/kg ° C (the specific heat of ethanol is 2.43, and methanol is 2.51).
Water/Alcohol to Fuel Ratio. Most experts suggest a maximum water to fuel ratio of 25% and point to many tuning problems with rations this high. Typically, 10-15% water to fuel is a more manageable ratio.

Re: other people using them...
Holy cow... 26 lb of boost! Wild... I wonder what he is dynoing at?
My numbers are with 15 lbs of boost. I was going to kick it up a notch and see where 17 lbs of boost will take me... I'll probably keep that for my street tune and then by summer get braver with 20 lbs of boost.
 
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