helpful hints and tips

Home-made intercooler sprayer/mister
-submitted by codesplice

To combat the issue of a heat-soaking intercooler that may cause higher intake temperatures and subsequent performance degredation, I designed a spraying system that would mist the IC with a cooling solution. For winter, I run 50% washer fluid in water, and in summer I'll use a 50% isopropyl alcohol solution.

After toying with the idea of commandeering the spray to the rear windshield washer for the purpose of an IC sprayer, I found a good deal on a washer tank with pump included from a Mazda Miata. I'd recommend checking eBay for such parts. If you've already done the intake resonator delete mod, the Miata tank fits very well below the intake where the resonator used to be. If you like having a quiet restricted intake, and plan to keep the resonator, you'll have to find another suitable location in the engine bay to install the tank.

parts Complete parts list:

  • Washer tank + pump (1)
  • Length of 1/4" aquarium hose or vacuum tubing (2)
  • Aquarium one-way check valve (3)
  • Aquarium/vacuum line T-fitting (4)
  • Washer nozzle or misting sprinkler (check the plumbing section of HomeDepot) (5)
  • Toggle switch (6)
  • Electrical tape
  • 18-24 gauge wire and wiretaps to fit (check RadioShack)
  • Plenty of zipties
  • The shoe pictured is optional

Now that you've got all your supplies, it's time to step back and decide how you're going to implement this glorious plan. I'd recommend lifting the front of the car via ramps or jackstands and removing the plastic underbody spoiler so you can see how (little) much room you have to work with. If you haven't removed your intake resonator (responsible for 25% of the restriction in the intake system), now would be a great time to remove it. Instructions as stated in the WIS: "Undo the screw and unhook the resonator by pressing it up and slightly outwards." Consider also where you will install your switch, where you will tap for the +12VDC needed by the pump, and how you'll route those electrical lines through the engine bay.

sprayer tankI installed my tank in the space left by the intake resonator, using several zipties to secure it (picture to left). Depending on the style of your tank, you'll have to be creative in mounting it. Since mine was installed low, I used an extra length of 1" hose connected to a hole I drilled in the cap of the tank to make filling easier.

Once your tank is installed, go on and find a way to get some power to the pump, preferably via your switch. I tapped the 8-gauge audio power cable between my battery and my audio amp. You could also try tapping the primary battery cable, running an auxilliary line to the battery, or even hardwiring in to the fuse box. I installed my fighter-pilot style toggle switch toward the top of the panel under the dash. I'm happy with that location - it's easily accessible but not in the way. From the switch, I ran a wire through the grommet in the firewall (located above the pedals). This can be tricky, and taping the wire to a coathanger and then pushing it through seems to be helpful. Once through the firewall, run the wire to the + side of the pump (it should be labeled - if not, experiment and see which terminal will make the motor spin the right way). I used zipties along the strut bar to secure wire. Then run a wire from the - side to the electrical chassis ground next to the stock airbox. It might be kinda hard to get to, so you can make your own chassis ground! Just pick another Torx screw and put a loop of exposed wire under it. Now your pump should work when you flip the toggle.

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toggle switch      switch position      ground

Run your hose next. You'll need to get it from the tank to a spot near the intercooler. In order to prevent a siphon effect from draining your tank completely each time you spray, run the line upward to a point above the washer tank. Use a T-fitting to run a short length of line to the check valve. Make sure the valve is installed so that air can flow into it but not out. If your valve is labeled with an airflow arrow, it needs to be pointed toward the T-fitting. I installed the siphon break behind the grill by running the hose above the two horns.

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siphon break       siphon break mounted

From there, bring the hose back down to a position where it can spray the IC. Finding places to ziptie the hose in position can be tricky. The sprinkler I used had about 6 inches of stiff hose before the adjustable nozzle at the end. I used this stiffness to my advantage, and used the vented panel next to the foglights to help hold it in place. I adjusted the nozzle for a decent mist, and angled it so it could spray the entire length of the IC from the side.

hose in vented panel

And now, I have a moderately effective IC spraying system. Using my ScanGauge OBD-II reader, I've observed that intake temps during hard runs are about 3 degrees lower with spray than without. After hard runs, I've also seen that the intake temps return to a normal range more quickly if I sprayed before the run. And this is from observations in the winter - I think the sprayer will make even more dramatic improvements in the heat of the summer.

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sprayer mist top view     sprayer mist front view

I haven't made any comparisons of different fluids yet, but obviously an alcohol solution would be ideal - the low boiling point (and extremely low freezing point) make it perfect for evaporating heat away from the IC without freezing in cold weather. Also, alcohol would prevent the development of algae in the lines. Washer fluid works well too - and they contain a small ammount of methanol alcohol that will also evaporate more quickly than water.

-Thanks again to John aka codesplice for the write-up
check out his page at :

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