alcohol injection

[Mirageman]

I currently running WI using 4mm and 7mm aquamist nozzles together. I am using washer fluid [30% methanol] starting at 15# boost. This has reduced my knock sum from 25 to 10 at 20#, but I can't feel any increase in power during WI. Many of the Buick GN drivers are using 100% denatured alcohol injection and 93 oct. gas claiming this works as good as race fuel.
Has anyone gone this route? If so how does alky work?

[doodlem]

My buddy at work and his friend are using alky and i am going to. They are able to run higher boost with less knock and get coolers intake temps.

[Defiant]

You're _starting_ at fifteen pounds? Isn't that a little late?

Anyway, neither WI nor AI are supposed to directly give you power, they're supposed to allow you to run higher tuning (boost, spark advance) levels without grenading the motor. All you should feel, if anything, is smoother running while injecting.

[nine5raptor]

Water will do you more good than alcohol as it has a higher specific heat. In order to really see the benefit of wi systems you have to either use it to a) make up for too small of an intercooler or b) use it instead of all of the extra fuel in the cylinder, a la lean it out.

oh, and I would start injecting at more like 8 psi. Your system will vary this, but for most, in order to develop adequate pressure, the pump needs to kick on about 8 psi to be spraying at around 12-15 and higher.

[DrZiplok]

Note also that most pump hardware won't deal with pure alcohol. I run smurf piss as well, and the Aquamist folks specifically warn against running *any* ethanol, or more than 50% methanol.

You want to start pumping at about 7-8psi so that you have a good mist going by the time you hit full boost. And as for your knock count, you need to get a couple of counts further down (below 7) and then you'll start to see the benefits as the ECU will then be advancing your timing.

It's enough though that you've cut knock in half - you've greatly increased your safety margin right there.

[kpt4321]

The power increases are mainly due to the ability to run moe boost and more timing advance, you just have to tune it as such.

Keep in mind that water has a much higher specific heat than alcohol, which means that a mass of water can absorb almost twice the heat energy then that same mass of alcohol could (4186 J/K/C, versus 2549 J/K/C).

The additional octane from the alcohol is moderate, but not as much of a difference as the cfooling effect from the water.

Generally, WI companies such as aquamist wil suggest that you run pure water when the conditions permit. However, this does not take into account the octane limitations we have when we run pump gas. I'm not sure what the most productive mixture would be for street performance, but I'm thinking it would be a mix of H2O and alky, and it is very doubtful you want to use only one or the other.

....Kyle T.
93 TSi AWD "TURBO4"