Hey gang,

I've inquired about this here a while back. I am sold on alky/water injection used in forced induction applications but haven't seen a lot about it with high compression normally aspirated engines. More specifically street engines.

Does anyone have any experience of info concerning this.

Thanks,

-Scott.

 

Alcohol injection is used in forced induction setups to try to stave of heat related detonation issues and to increase air density. The thing is that it needs to be injected into the air stream to work and not just in the intake runner. The heat of compression in the cylinder will still cause problems with pump gas with a high compression engine.
Extra fuel will also displace air in a possibly restricted inlet combination as well. As alky will require 2+ times as much fuel compared to gas.(if using methanol)
Not to mention the fact that you will run out of methanol at some point, and that could really suck.

 

A light spray at WOT may allow you to run a few degrees more timing with pump gas would be about the only advantage, so you might get 10-20 more hp out of it, then there comes a point where too much timing is detremental no matter if you have detonation/knock or not.
You would still need to watch your alky level and make sure you don't run out, if it only kicks on at WOT you wouldn't be using any more than for a supercharged/turbo app, probably even less since you would not need to spray near as much in this case.
I use it on my turbo Buick GN with pure methanol and it works fabulously up to 28 lbs of boost on pump 93 gas.

 

As Mark was saying, alky injection works on boosted motors because boosting adds a lot of heat. The alky evaporating cools the air back down. NA you do not have all this extra heat so alky injection offers a whole lot less potential.

 

Thanks guys,

Alky/water injection is used to prevent/eliminate detonation....Correct?

I guess what I really want to know is if ........

You can run 28psi on 93 with meth then why not a 13:1 NA motor on 93 with meth?

Thanks again,

-Scott.

 

The problem with having that much compression, you need higher octane pretty much at all rpms/loads, therefore you would have to have alky spraying all the time, and that just is not feasible. Now for the other case where you can run at cruise and lite acceleration with pump gas and just use the alky when at WOT so you can up the timing a bit is the only advantage to using alky with a NA motor, but the advantages would be small even in that case.

 

I'm running verrrrry near 13:1 static with a drc of 8.9:1 on the street in all traffic conditions on 92 octane. Not a issue with a water injection/alky kit. I just use wiper juice in it

Sure I had to pull the timing back too 34 degrees total to be conserveitive [sp?] on the 92 octane