To get the best possible performance from our intercoler water sprayer spraying we need to focus on three main areas
Ease of Evaporation
Efficient Use of Water
Julian Edgar has done an excellent video here which more or less covers the points in this article
1. Ease of evaporation. We need to make it as easy as possible for the water we are spraying to evaporate. The transition from a fluid to a gas is what sucks the temperature out of the air/surface.
To make it easy for water to evaporate we need to create the finest mist we possibly can. We want the absolute highest surface area:volume ratio we can get.
Two methods to achieve this.
Pressure. Regardless of the jet we are using, the higher the pressure of the water flowing through it, the finer the water droplets will be. In short, we need to use the highest pressure pump we can.
A windscreen wiper pump may get us up and running but it is far from ideal, it won’t get the pressure high enough to atomise the water and it will flow too much water through a conventional non-atomising nozzle.
We need a high pressure pump, preferably a pump that can support 40PSI plus. Diaphragm types pumps are probably the most suitable, they can maintain high pressures, don’t flow huge volumes (which makes them cheaper) and they can pull water from below which makes finding a mounting spot for one easier.
Jet/Nozzle. Okay, I said pressure helps any jet but to get to that magic atomisation we need an atomisation jet/nozzle, a jet which is designed to make the water mist as it flows out of the orifice.
Or alternatively, atomisation nozzles from your local garden supplies store or auction website should turn up some low cost alternatives also.
2.Spray Targeting. This might sound obvious but the spray should be targeted at the hottest part of the intercooler. The hottest part of the intercooler will have the greatest temperature differential versus the water mist we are spraying, this makes evaporation happen faster.
If you are using more than one nozzle start by aiming nozzles at the hottest part and work your way out.
3.Efficiency. Drowning the intercooler in water is not only inefficient but it is also not effective. As we said at the start, the real heat removal comes when water changes from a liquid to a gas. If we have big drops of water saturating the fins on the intercooler this evaporative cooling is going to be severely reduced. It also uses a lot of water.
When we have got our components setup we need to find the best way of using them.
To find the best spraying method we need to experiment and to experiment we need to be consistent with our spraying ie spraying for the same amount of time and in the same circumstances. Comparing back to back tests we can pin point the best method.
When we have found the optimum method we need to be able to replicate this method consistently. Doing this manually in a race environment is out of the question which is why we are creating the “Intercooler Spray Manager“.
We program the unit with the best spray strategy we found in our testing, the Intercooler Spray Manager looks after the spraying process for us, we just need to keep the tank filled!
When we have an intercooler sprayer setup that operates with high pressure, that uses atomistaion nozzles, whose nozzles are targeted at the best areas and whose operation is automatic and consistent we can dramatically improve the effectiveness of our existing intercooler, be it the stock cooler or an aftermarket item.