A closer look at water injection like all good stories should start by looking at a brief history on water injection systems and where it is today. Water injection systems have been around ever since its first trial by an engineer named Benki in 1900. Soon it was -adopted by both the Royal Air Force and the US Air Force in their turbo-prop World War II fighter planes to cool intake temperatures in the aircraft’s engine. The system was also used in the Formula One Racing by none other than Ferrari in the 1980’s and presently it is has been accepted as standard on many of the World Rally Championship (WRC) cars.

Many of the disbelievers of this technology make it to be some type of snake oil. However, after reading the previous paragraph ask yourself this one question: why would manufacturers such as Ferrari with millions of dollars to spend on these competition cars use anything that has not proven to be beneficial in the cutting-edge sort of way, much less for something that certain people refer to as a ‘quick fix’! The only reason that therefore explains why water injection has not been much more readily accepted as perhaps the single greatest power adder to any turbocharged or supercharged vehicle can only be the lack of proper researched information!

The basic theory behind water injection is that it works similar to a fuel injection system, just that instead of fuel, water or methanol (or 100% alcohol) is injected into the airstream. It should be stated that this is not the same as intercooler spraying which (without getting into details) is far less efficient, far less sophisticated and in the longer-term more expensive to maintain.

The primary purpose of water injection is however the same yet it does much, much more than just temporarily freezing an intercooler. This purpose is to cool the heated air that a turbocharger or supercharger compresses and blows into the engine. The hotter the air temperature the thinner the air becomes. This means two things; firstly the thinner air is less dense and so will not prove as combustible as denser air and secondly, the hotter the air going into the combustion chamber, the higher the risk of detonation (if you’re not yet familiar with this term, now would be a good time to research it). Water injection also helps to burn the air/fuel mixture more efficiently and helps prevent detonation. If methanol is used, not only will this have a cooling effect on the air charge but the air/fuel mixture is further enriched by the flammable alcohol being injected.

The basic water injection system comprises of a pressure sensor, a water pump, a solenoid and a reservoir tank to store the water. It operates as follows: when the boost pressure exceeds that set by the pressure sensor, the pump switches on and the solenoid sprays the water as a fine mist directly into the charge. Most systems usually allow for the nozzle to spray either into the throttle body inlet or into the intake manifold directly, when the boost pressure falls below the level the pressure sensor is programmed for, the pump switches off.

Now the important question, does this really work? The test of any good water injection system would be to compare dynographs with pulls being made with and without the use of water injection and take simultaneous readings of the exhaust gas temperatures to determine how much the combustion temperatures have ‘cooled down’ by. Also useful would be to plot knock sensor data for eg, when using an Air Flow Converter that is able to display such information, to show the decrease in detonation.

Such tests have been proven time and again with many different vehicles. Do as much research as one would like, but only after installing and using it would one know the real benefits. And anyone who has used water injection and says that this is not a worthwhile modification either lives in the arctic or is completely off their rocker!