Ok, so what kind of alcohol are you supposed to use, and exactly how much? What are the dangers of doing this?

 

denatured alcohol. it depends on how bad your results are, overtemping the engine and blowing something up if you stress it.

TR

this is copied from the FAQ section https://www.rx7club.com/showthread.p...06#post5131106

My car is having trouble passing emissions, but I have new spark plugs, filters, cats, etc. What do I do?

and:
J-rats Recipe for cheating emissions if its ABSOLUTELY necessary:

1. Turn variable resistor to full lean, or as lean as you can get and still run.
2. Trick ACV into pumping air to the cat all the time by removing the FORWARD UPPER vac hose, and capping it.
3. Run 87 octane
4. Run your tank down till your almost empty.
5. 2-3 bottles of alcohol in the tank. Drive VERY GINGERLY to the emissions station.
6. Once you pass go, DIRECTLY to a gas station and fill up with regular unleaded.

 

all i know is that i put a bottle of rubbing alcohol in a 1/4 tank of gas in a warm engine and i passed emissions with flying colors in my 1990 na a few years ago . DO NOT TAKE THIS AS FACT ! i do not want to be responsible for a popped motor . im just stating a past experience .

 

You probably don't want to use rubbing alcohol because it is about half water. Get the denatured alchohol at Lowes or Home depot in the paint supplies.
Definately run your tank down so you don't have to put as much alcohol in to get a higher mixture, then when done fill it so it's more dilluted and will have less adverse affects.

 

With alcohol(methanol or ethanol) mixed into the gas, you will run leaner than normal. This is why you shouldnt go under heavy load with it in your tank.

It probably wont permanently affect your engine at cruise settings, other than poor running(functional closed loop will help alleviate the problem). It WILL react with any rubber you have in the fuel system, and quite quickly(within a day). The higher the alcohol % the worse the effect. Basically it causes the rubber to swell up and expand permanently. It theoretically will cause aluminum to corrode, but on a much longer term basis. Steel or stainless will not really be affected.

I've run 20% methanol by volume in my tank before. But this is short term basis, couple of weeks, and i still have to take apart everything to make sure its ok.