Water Injection
You may have noticed that our 440 combination was running high boost without the aid of an intercooler. It's a fact of physics that compressing a gas (air in this case) produces heat. In practical terms, that means more boost equals more heat in the incoming charge. It's well known that high-inlet air temperature saps power and encourages detonation, hence the need for a means of charge cooling, especially with a lot of boost. Cooling the air/fuel charge is typically accomplished by employing a heat-exchanging unit known as an intercooler. Essentially, an intercooler is a radiator through which the induction charge is passed and cooled by the temperature differential between the high-temperature inlet air and the cooling medium-ambient air in an air-to-air intercooler.
The system favored by The Supercharger Store is a departure from a conventional intercooler, and actually borrows from technology employed in supercharged WWII fighter aircraft-water injection. Water injection provides a cooling effect to the charge through another effect of physics, the latent heat of vaporization. As a highly-atomized liquid changes to vapor, the process consumes heat. The Supercharger Store's system provides a high-pressure pump that is triggered by a pressure switch, which in turn is referenced to boost. When the boost hits the prescribed pressure level, the pump sends high-pressure water to a fine-atomizing nozzle aimed at the blower intake. Water provides the cooling and also acts as a detonation suppressant. The kit is complete, with all of the fittings, tubes, an anti-siphon valve, and a fuel cell to serve as the holding tank.
With the water injection properly setup, Bob Woods of The Supercharger Store reports phenomenal power output on pump gas. Various kits are sized with nozzles designed to differ the fluid flow rate for different output levels, with some of the higher horsepower kits featuring two stages of injection for outputs of up to 2,000 hp. The system can be used with straight water or various concentrations of water/methanol mix. Bob recommends common windshield washer solution, which contains up to 25-percent methanol. Water injection is far from a new idea, but with the output capabilities of modern supercharger systems it's an innovative solution for power on pump gas.
 When activated by a boost-referenced...  When activated by a boost-referenced switch, the water-injection nozzle sprays a fine mist of cooling water directly into the compressor inlet. The effect is charge cooling. A cooler charge makes more power and reduces the tendency to detonate, while detonation suppression is further augmented by the introduction of water to the combustion process. |
 The water-injection kit is...  The water-injection kit is complete with a fuel cell to hold the fluid, a high-pressure pump, the pressure switch, a check valve, and all of the tubing is supplied with quick-disconnect fittings. It's all there, and we had it quickly rigged for dyno duty. |
 Various blends of water and...  Various blends of water and methanol can be substituted for straight water. An easy way to get an appropriate blend of methanol/water is to use windshield washer fluid, as recommended by The Supercharger Store. Formulations vary in percentages and for winter/summer grades. Check the product data sheet or label for the contents, or get a recommendation on brands from The Supercharger Store. |