Water Injection on a high compression NA

Anyone have any proven information about the benifits of water injection on a NA engine? I'm building a high compression motor, 12.5ish:1 with full engine managment, 93 octane. Its common knowledge that water injection will reduce knock allowing you to advance the timing a little, but alot of people say that the room taken up in the cylinder by the water vapor, as well as the slower burn would reduce hp to the point that increasing the compression to the point of say 13:1 would yeild less power than lower compression without the water injection - but after researching this off and on for the past few months it seems that its all based (both sides) on sketchy logic and nobody has any real proof. I'm also talking about comercially available tuneable water injection units that very injection amount per rpm, are tuneable, and have real injectors; not just a windshield squirter pump with a nozel.

I read an article a while ago, where someone took a Ford Fiesta and raised the CR to 13 or 14:1, I can't remember, and was using a computer fed water injection setup (aquamist, injector etc) to handle detonation. His goal for doing it was to achieve the highest MPG possible. Think he was pulling off 55mpg.

If you want my honest opinion, why screw around with water? Use alcohol in place of water. Way more effective, more power and not all that expensive. The amount you'd need to inject would be dependant on main tank octane and CR of course, but hell....15:1 CR sounds good.

Yeah I'm open to the option of replacing water with other stuff, just didnt mention that in the orgional post. I have read the artical you are refering to (or ones very similar to it anyway).

well, can't say I've ever read any good articles on injection-anything in regards to NA and power....but from what I've read about boosted engines and injection, water is a poor substitute for alcohol.

It would be an interesting experiment. The water injection systems you are contemplating are also designed for alcohol. I know I'd love to hear your results between the two.....and the combination of the two. Either way, you'd have something that worked well. Just a question of how much the "additive" was costing you....

So I guess it is an unknown territory?

Try propane.....

talk to curtis. I think he mentioned doing this. He had a bad experence of running out of water on a long trip.

However, do use an alcohol/water mixture. When alcohol evaporates it cools the surrounding air. It also adds fule of high octane along with your water reducing "knock."

Good luck with it :)

Alcohol cools the intake track less as it evaperates.