About the Intercooler Sprayer

Q. What does it do?

A. The sprayer squirts the intercooler with water mist to increase the amount of heat removed from the intake charge.

Q. Where's the tank?

A. Under the hood, on the driver's side behind the headlamp.

Q. What do I put in the tank?

A. Washer fluid. Plain water could freeze and crack your sprayer plumbing in winter, and it's more prone to growing algae and stuff like that.

On the other hand, Subaru recommends regular water for their water sprayer on the WRX STi. They just suggest you run it dry if it's going to be freezing.

Q. What does the "Manual" and "Auto" switch do?

A. Manual squirts the intercooler for as long as you hold it down (and as long as you have fluid). Auto runs the sprayer in an on/off pattern. The ECU supposedly uses mass air metering and throttle position sensor to figure out when to trigger the sprayer. At some point we'll figure out the on/off logic, but at this point we haven't spent the time to figure it out... :)

Q. How come it keeps dripping on my foot when I fill it?

A. It has a drain that's part-way down the neck. If you fill past that it'll just dribble out on the ground.