Topic: How to- Pressure activated intercooler sprayer.

[Cbxj]

Some background- I swapped a ej20k into a leggy outback, a 97 that has a stock little hoodscoop (usually blocked off with a blocker plate). I "enhanced" the airflow thru the intercooler with modified WRX splitter, and some creative use of black closed cell foam. I figure it's pushing as much air thru the intercooler as possible without changing the scoop itself.
A while ago I picked up an I\C spray switch, nozzles and a tank that goes in the lefthand side fender from a JDM (thanks Sonny). For a short while I had the I/C spray on a micro switch activated by throttle position, for a pump I found an in line washer fluid pump from an Audi at the wreckers (Audi cars seem to spray LOTS of W/Washer )
I really was not happy with the micro switch activation.
What I have settled on is using a pressure switch available at GREGGS Distributing Part number 76576-10 (normally open, activated at 10 psi), these are adjustable +- 2 psi, & there are other pressures available, and the price was great.... 30 something dollars, with a barbed fitting to go with it.
Plumbed into my boost pressure gauge line, the hardest part was getting the right combo of fittings and clamps to use on the tiny 1/8th inch OD line my gauge came with.. yours may vary.
I also wired in a little light at the top of my dash that comes on when the sprayer is activated, as a bonus it's a handy little tell tale that reminds you that your into the over 10 psi zone, and burning fuel like speedboat.
I kept the I/C switch to use manually, and have mounted that in the console (the switch is the same size as a seat heater switch), so if I have a passenger they can easily reach the switch if required.
Parts list:
W/W tubing-any auto store
In line pump-wreckers or aftermarket (Part Source)
18 G wire-MRO electronics
Pressure switch-Greggs Distributing
Fittings for vacuum line or boost gauge line (If doing it again I would have mounted the pressure switch in the engine bay and cut into a vacuum line rather than mess with that tiny gauge line)-Greggs Distributing
Tank -WSC! OR wreckers?
Momentary switch-WSC! or MRO electronics- has lots to choose from
Sprayer nozzles-Princess Auto or wreckers

NOTE if you had a sedan, you could just use a tank from a wagon and use the rear sprayer pump BUT that would mean going thru a lot of windshield washer fluid in the summer, with a separate tank you can just use water all summer and the cheapest W/washer fluid you can find in the winter, instead of the expensive rainX that I'm hooked on.

Anyway, it all comes together quite well and is a slick working system, for not much dough. If I get really crazy I may hook up some thermocouples and a logger and see what effect, if any, spraying the intercooler does. but that would be a summer activity. Feel free to contact me if you have questions.

[GC8REX]

Exact same setup as I installed in my WRX, except my pressure switch was a different brand off ebay.

Works very well indeed!

[ZiG]

NOTE if you had a sedan, you could just use a tank from a wagon and use the rear sprayer pump BUT that would mean going thru a lot of windshield washer fluid in the summer, with a separate tank you can just use water all summer and the cheapest W/washer fluid you can find in the winter, instead of the expensive rainX that I'm hooked on.

Nice writeup, and good idea. I feel the need to point out though, that spraying WW fluid on an intercooler is nowhere near as effective as water. WW fluid is alcohol based (which is how it dries streak-free and doesnt freeze in winter) and alcohol has a MUCH lower specific heat capacity than water.

As for spraying in the winter, well, I figure if it's cold enough outside that your water tank freezes, it's probably cold enough that you dont need to be spraying.

[Cbxj]

Yeah (spraying on winter) I'm more worried about the water freezing and wrecking the tank or pump, hence the w/w.

[astroboy]

Very cool. Pics please!

[ZiG]

Yeah (spraying on winter) I'm more worried about the water freezing and wrecking the tank or pump, hence the w/w.

Nah. Long as the tank isn't completely full to the top, you're fine. Mine froze and thawed just fine the last two winters.