Manifold Water Injection
 

This is something that I have planned to do from the start. While putting my own ideas together I got in contact with club members who had similar ideas. Eventually they started their own tuning business called PiNZ and have built a complete electronic controlled water injection system.

The model I have at the moment is still a prototype, but functionally does everything the production model will do. It has a pump that can run pressures from 20spi to 100psi, it can be activated to come on at any pre-set boost and the pressure is mapped to the engines rpm. This allows me to have water injected at low rpm and not cause misfires and have the appropriate amount of water at high rpm.

The benefits of water injection into the manifold are:

• Run higher boost levels

• Run advanced ignition timing

• Run a leaner fuel mix

• Reduced chance of detonation

• Cooler intake temperatures

• Cleaner engine internals

The reduced chance of detonation is a result of two properties of water injection. The fine water spray will absorb 6 times the heat energy from the compressed air than the same volume of petrol. Typically 20% or more of the fuel injected in a turbo engine is there just for cooling. The second advantage is that the water molecules during the combustion stage actually slow the flame front, this gives the same effect as using a higher octane fuel.

For less than the cost of a large inter-cooler, I not only get the cooling effects, but these other advantages too.

Installation

Because my small after market inter-cooler has aluminium pipes, I was able to weld a nozzle mount to the top pipe. I routed the high pressure nylon hose to the rear of the car where I have mounted the pump and pressure sensor and taped into the rear window washer reservoir.