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WATER INJECTION FOR YOUR POWER-THIRSTY ENGINE

Author

Sean Greene

Photography by Nick Chin

You have to admit that the thought of injecting water into your engine sounds crazy. We all know that water doesn’t burn and it can’t be compressed. Those unfortunate souls who have tried to do this now have engines that are the equivalent of ship anchors. In this installation, we aren’t going to be injecting huge amounts of water into an engine, but rather a fine mist that’s proportionate to the fuel flow (10 percent to 20 percent), using a high-pressure pump. This will help lower the chances of detonation by reducing the intake charge temperature.

Why water? If you read HCI’s intercooler article in the April ’04 issue (“Chill Out,” p. 131), you know that water has a large capacity to retain heat. So when water is introduced into a hot environment, a percentage of heat is absorbed. This is effective when installed on an internal combustion engine, especially when it’s supercharged or turbocharged.

South Florida Performance (SFP) installed the Aquamist System 2s, which comes with a controller that is capable of adjusting the system at different rpms (2,000-9,000). It’s adjustable in 1,000rpm increments and has the option of 3D mapping when used with a MAP sensor. The owner of this ’03 Mitsubishi EVO VIII has intentions of pushing the envelope and eventually installing standalone engine management, so he wanted a system that would be fairly flexible.

The Aquamist system isn’t a power-adder like nitrous oxide, so if you are expecting to see a direct increase in power after installing this product you will be disappointed. However, your engine will be able to make more power because of it. Confused? Remember that water is being injected to help suppress the chances of detonation and with less detonation, you can turn the boost up higher or run more timing. Naturally, if you have access to good gas like 94 octane, you will be able to run more boost than someone will on 92 octane; but with the Aquamist you can squeeze out even more power.

It should be noted that the Aquamist system isn’t a substitute for an intercooler, but more like an add-on. Imagine combining this product with an intercooler and intercooler chiller such as the Nitrous Express N-tercooler. To increase the effectiveness of the Aquamist system, SFP opted to use a fifty-fifty mixture of methanol and water. Methanol has an octane rating of 113 that will increase the fuel quality and the cooling capacity of the water.

This product works on a wide variety of vehicles, both naturally aspirated and force-fed. The system will help reduce detonation; however, if your engine is detonating before you purchase this product, you should put your money into solving the problem first. The Aquamist will not make existing problems disappear.

The upper intercooler pipe must be removed in order to install the Aquamist nozzle.

This is achieved by loosening the hose clamps at the throttle body and intercooler.

With the pipe out of the way, a suitable location for the Aquamist pump and relay can be selected.

Here we can see the rather beefy pump, which will be mounted just below the air filter on the side of the chassis. Pilot holes are drilled first.

Pilot holes are drilled first.

The pump is bolted securely to the car.

Next is the water reservoir that must be modified in order to work with the Aquamist system. SFP changed the height of the system, as pouring the methanol/water mixture into the reservoir at its original location would increase the chances of spillage and damage to the finish of the vehicle. The high-pressure tubing is also installed while the reservoir is out of the vehicle.

The tubing is measured for length and cut accordingly.

With the car raised off the ground, the feed tube can be connected to the pump using the fittings provided.

The wiring to the pump is hooked up next. Since the vehicle is intended to be a show car, the wiring must be tidy. The best way to accomplish this is to measure out proper lengths needed and then group the wires together. The control unit for the Aquamist is concealed inside the passenger compartment, where basic connections such as ignition power and ground are made. Also, inputs for rpm and pressure are connected to sensors on the engine.

By covering the wires in split-loom tubing, they blend into the factory wiring.