During WWII water/methanol injection was used by both the Allies and Axis powers to increase the output power of their supercharged aircraft engines.  By spraying a fine mist of a water/methanol mixture into the intake of these large engines, gains of 350-500hp were achieved. This allowed fighters and bombers to carry heavier loads at increased speeds. Water injection was also used in Formula 1 racing in the early 60’s but was quickly banned for adding to much horse power to the engines. It is also banned in NASCAR racing.

Water is able to absorb huge amounts of heat. In supercharged and turbo charged engines, heat is a major problem and inter coolers are used to reduce the heat of that compressed air. By spraying water into the air charge, the heat is absorbed and the air/fuel mixture becomes denser. Using a 50/50 mix of water and methanol, further heat reduction is possible with a substantial increase in octane because of the methanol. You can increase the octane rating 8-16 points which can save you money over buying higher octane gas
Methanol Water Injection Tube

The other effect that water injection has on the engine is its ability to reduce or eliminate detonation also known as pre ignition. Detonation is the audible sound called "pinging" or "knocking" commonly caused by using low octane fuel. Detonation occurs when newly introduced fuel ignites before the spark plug fires. This causes double flame front and increased cylinder pressures which can cause catastrophic damage to the engine. In modern computer controlled engines, a knock sensor is used to detect detonation. When it does, the computer retards ignition timing to stop pre ignition but also robs the engine of power and fuel economy. Water injection will absorb the heat that causes pre ignition allowing the engine to keep its timing advance and produce peak power.

There are many companies that have developed very good systems for supercharged and turbo charged engines. Few have systems for non-boosted engines. Water injection will also help vehicles that are driven in hot climates or when they are used for towing. My primary objective was to see if improvement in gas mileage was possible. Only when methanol or alcohol was mixed with the water did I see an improvement. The purpose of this site is to share the knowledge and experience I have acquired in designing and building my own system.