What is the purpose of a water injection system?
It is designed to let you safely run higher boost on a high compression engine (like that which is supercharged). It probably won’t do anything for a stock engine, unless you bump compression so high that it detonates. The water cools the intake by 60-100 degrees F depending on the ambient temp and altitude. The hotter it is outside, the more it cools. It does this through the heat of vaporization of the water. The water also raises the apparent octane of the fuel by 10%, meaning it makes 93 octane run like 102. This is because the cooler charge burns slower and resists preignition. Another benefit is buffering of the combustion process and smoothing of the power strokes (that is, a tremendous increase in detonation resistance). All this allows you to run full timing advance and make more power. The overall result is the same effect as an intercooler, but you don’t have to increase the boost on the supercharger to make up for intercooler losses. That means less supercharger drag. Drawb
