Using water injection (or water / methanol as it is sometimes referred as) has advantages to building more power. It cools and eliminates or reduces knock (detonation) which allows for higher PSI boost on the engine safely. Of course there are a few more details to it that this simplistic version but it has been around since WW II so it is not new technology by any means!

The water cools down the cylinder temperatures. It also helps clean away carbo deposits which can cause hot spots leading to engine failure.

I use the AQUAMIST 2D system with a DDS3 in cab controller/gauge. This is in my opinion the very best water injection system out there. A little more spendy but it does so much more than lesser units.

It uses a 100psi pump and the system is under 100psi the entire time (pre-pressurized system) so there is absolutely no delay in delivering the fluid to the injector nozzles.

I currently use (1) 1mm jet that delivers approximately 310 cc which translates to about 10% fuel ratio using (6) 550 cc fuel injectors. It is set to inject when boost is above 15.5psi.

A double advantage in this system is my HKS fan controller includes a sprayer function that will sub-control the same system but re-route it (if not under boost) to 3 sprayer nozzles. 1 for the radiator and 1 for each side mount intercooler. This helps resolve intercooler heat-soak if doing a lot of high boost runs.

I run a mixture of 70/30. 70% water with 30% methanol. The methanol prevents freezing. Some run 50/50 as a maximum but I find 70/30 works much better. More than 50% alcohol or methanol and the system is degraded from doing what it is designed to do.

\Contrary to what some people think the methanol has nothing to do with the anti-detonation function of the system. All it does is prevent the water from freezing. the WATER is what is cooling and prevention knock. Period. It might be "cool" to say "METH INJECTION" but that is a totally inaccurate term and, in my opinion, usually used by people that haven't a clue of what they are talking about. The proper is water injection. Not as glamorous but that is the proper term.

This was the setup when I had the FMIC installed:

1mm injector, flow sensor, and 30cc accumulator tank. The manifold pressure switch and tie in to sprayer option is above where the headlight goes. The other wire on the intercooler pipe (to the left of the injector nozzle) is the intercooler temp readout sensor (out readings).

Below is the current setup after moving everything due to changing back to SMIC (and ditching the FMIC). Everything had to be moved from below due to re-installing the intercooler to side mount. It all fit behind the passenger headlight after some careful modifications. Pump and tank stayed the same (under the main circuit break panel, passenger side).