Quality DIY intercooler sprayer for under $50.

[573]

I'm certainly not the first person to do this, but I haven't seen anybody else get this good of results for so little money. With that being said, I'll continue with the post, which is really just a copy/paste from my blog. Since this was originally a blog post, it does not have the traditional step by step DIY format. Sorry about that.


Once I felt my intercooler after a few runs of auto-x, I knew I had to do something about heat soak. An intercooler sprayer seemed to be a relatively cheap/easy way to help deal with that. My goal was to cleanly install a quality IC sprayer for $40 or less. It's hard to do much of anything car related for $40, let alone something nice. Because of this budget, I went to ebay. I found a pressure switch that is perfect for this project, and a windshield washer kit. You can do this for even less money by not getting the pressure switch, but I wanted an automatic setting that runs the sprayer once a certain level of boost is reached. I also had to get a few misc items from Home Depot, but even so, I did a pretty good job of sticking to the budget.

This is the pressure switch I got: http://www.aquastealth.com/browsepro...re-switch.html This same item can be purchased on ebay for the same price. The one that can be triggered by 2-24psi is ideal.
This is the sprayer kit I got: http://www.carparts.com/autoparts/Pr...dshield+washer The overall quality of this kit is pretty low, but the pump and tubing, the only parts from it I used, are great. Also, it was $15. This kit does come with nozzles and a reservoir, but both are complete crap.

To save on weight, space, and money, I tapped into the windshield washer reservoir. To do so, I drilled a hole and added a brass fitting that I got from Home Depot. I then threaded it in and sealed it with silicon caulk. The pump is also mounted on the OEM reservoir. On my car, the tank is mounted inside the bumper/fender. To gain access, you will need to jack the car up a bit and peel back the fender liner.






Since I am using a pressure switch to trigger this, I had to run a boost line to the inside of the car. You could always mount the switch in the engine bay, but for the sake of reliability, I mount all my electronics inside the car. I already had a boost gauge that is tapped into the hose exiting the bypass valve, so I fitted a different tube to that and used a T splitter inside to enable both the pressure switch and the boost gauge to get pressure readings. At the same time, I ran a wire from the pressure switch, though the firewall, and to the sprayer reservoir where the pump was to be mounted. I also ran the tubing from the IC splitter down to the tank, because it follows virtually the same path.








For the electrical side of things, I put 2 switches in the change compartment/fuse panel door. The rocker switch in the center puts the sprayer on automatic, so that it is triggered by a predetermined amount of boost. The red push button(came with the sprayer kit) sprays the IC regardless of the boost level. This button is intended to be used between auto-x and rally-x runs to help combat heat soak. The pressure switch has 3 pins. One is "common", which I connected to the pump, the other is "normally closed", I connected this one to the push button. The 3rd pin is "normally open". I connected this pin to the rocker switch. For power, I tapped into the anti-lock brake fuse slot. I already had wires coming out of this spot for a disable switch, so that was easy. I used a 10 amp inline fuse to protect the sprayer system. The switch on the left is unrelated to this project, but it disables the anti-lock brakes.


When it came to nozzle selection, I was unsure as to which path I would take. The nozzles that came with the kit were junk. They were made of plastic and had terrible spray patterns. I thought about ordering nozzles from Mcmaster, but, at $10 each, they were horribly overpriced. I had some extra tubing and a T splitter laying around, so I made a ring of tubing to go around the perimeter of the IC. I drilled small holes in the tube, and ended up with a nice even spray that covered the entire IC. I mounted the tube with zip ties. I drilled a pair of holes in my splitter every inch, and ran the ties through those. My splitter was a DIY project, as well, so I drilled into it without hesitation. I have yet to get one, but I would highly suggest putting a check valve right before the nozzles(in my case, tubing) so the system will be more responsive. Currently, there is about a 1 second delay between when I push the button and when water flows out.




And here is a video of this thing in action. As you can see, it has a pretty healthy spray.

http://www.youtube.com/watch?v=qj3s02N7tNo

I'm pretty happy with how this ended up. It certainly won't have a big impact on performance, but it was cheap and added minimal weight. Also, anything that reduces intake temperatures will provide some benefit. If you're thinking about doing this mod, I say go for it.

I have some more DIY things on here: http://www.cgbagne.com/wrx/

[MConte05]

Great writeup! I was just about to get started on my own personal design after this weekend's Rallycross and I was spraying water on my intercooler between runs with my spray bottle.

*EDIT* My only suggestion is to try and find nozzles that produce a fine spray, as the finer the spray, the better the heat removal is.

[573]

Originally Posted by MConte05

Great writeup! I was just about to get started on my own personal design after this weekend's Rallycross and I was spraying water on my intercooler between runs with my spray bottle.

*EDIT* My only suggestion is to try and find nozzles that produce a fine spray, as the finer the spray, the better the heat removal is.

Thanks for the input. I'll keep my eye open for some misting nozzles. I have looked some, but the stores I've been to had nothing of the sort. I'll probably try a garden store next, and if they don't have any, I'll just order something.

[MConte05]

I am starting to put together my kit now, and I think I am leaning towards some of the McMaster carr nozzles, found quite a bunch for less than $5. Check out part numbers 30995K32, 3404K73, or anything under Spray Nozzles or Atomizing Nozzles. I think you'll find quite a bit of interesting ones.

Also some stuff on here: http://www.cloudtops.com/fogging_system_parts.htm

Go all the way to the bottom of the page there, for a barbed one, real cheap.

[rollo]

Interesting - I attempted this (in a MUCH more bodgy way) many years ago on the Corrado - its weedy little IC is in front of the drivers side wheel with a duct leading to it. I literally cut the windshield washer tube, hooked it to a piece of tubing that I ran into a hole in the IC duct, and put a misting nozzle on the end. It was <$10 all told, worked pretty well, no extra electrics, and was easily reversible for times when I might need the washers again.

That was before I had a house and a sprinkler/irrigation system, so I had no clue about that stuff. If I was gonna bodge it again (and I might, seeing this), I'd most likely go with the 1/4" irrigation line - the barbed connectors are great - and probably a hanging basket misting kit, they create a really fine mist and are adjustable. Home Depot or Lowes both carry a wide selection of such things (either next to the plumbing aisle or outside in garden).

[95 WRX STi]

This sounds like a good idea for those who don't have the luxury of already having the JDM STi's. My 95 actually came from the factory with a seperate jug (labled "water only") and the "I/C SPRAY" button on the dash. The nozzles look similar to what you used, and the jug is also similar. Good job, great write up, and nice pix!

[xbmxxx]

I was reading on another site about this, and everyone was freaking out about people using washer fluid to spray their i/c. Something about it containing methanol.