HOW-TO: DIY Intercooler Water Sprayer

ChopstickHero

zoom zoom, eh?
Contributor
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2003 Subaru WRX Wagon, 2000 Miata
CAN A MODERATOR MOVE THIS TO THE HOW-TO FORUM? THANKS!

I want to give credit to TreeFiddy from MOCC. He was the one who did it a while ago and inspired me to do it as well. He has a FMIC though, but pretty much it's the same thing.

Items required:
1 Protege washer pump (used one is cheapest) - $12 shipped from a member here
1/4" black microtubing (comes in 50ft roll - Home Depot) - $2.99
10/32" thread 180[SIZE=-1] jet sprayer (comes in pack of 10 - Home Depot) - $2.67
Dremel (rotary tool)
20 ft of wire (16 or 18 gauge - Home Depot) - $3.60
3 Spade connectors (2 plug-type for the pump, 1 U-shape for a ground - Radio Shack)
Momentary push button switch (or switch of your choice - Radio Shack) - $2.50
The blank space holder beside your dimmer switch (free!)
Soldering iron and solder
Electrical tape
Industrial strength Velcro
Thick sticky tape
[/SIZE][SIZE=-1]Basic hand tools

My total cost (because I had alot of the items already on the list): $25

Step 1: Take the blank space holder beside your dimmer switch out of your car. Depending on what type of switch you have, the hole size will be different. I got a push button momentary switch. This means that the contacts only connect when you push it and when you release, it will disconnect. I thought this was a better idea than a toggle switch, as you might accidentally leave the toggle on and either burn the washer pump or use up all the water in the reservoir. Anyways, using your rotary tool, drill about a 1/2" hole to fit the push button switch. Using the wire and soldering iron, solder the wires to the switch. Use electrical tape to tape them up good. Feed the wires through the space holder. I didn't need to use any adhesive to stick the switch to the space holder. It'll fit snugly if you didn't drill the hole too big.

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Step 2
: Remove the front bumper. If you don't know how, look it up in the Protege workshop manual.

[/SIZE][SIZE=-1]Step 3: Remove the washer reservoir. Unclip the plug to the washer pump and unclip the wire holder. Take out the two 10mm bolts holding it in. Detach the washer fluid line that goes to the pump. It will start leaking so use a rag to prevent it from spilling everywhere.

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Step 4: Empty the reservoir and then locate the marking for a hole in the spot for the other washer pump (how convenient!). The reservoir is actually the same as the Protege5 one, except the hole is not precut and no rear washer pump is present. You'll notice that the hole is already outlined. I drew it in with a Sharpie so that you can see it. Take your rotary tool and drill the reservoir (goodbye smiley face). Make sure you go rinse the shavings out of the reservoir after you finish shaping the hole. It's easier if you put the rubber grommets into the hole first. Lubricate the inside of the grommet with a little water and the washer pump will slide in easier. I decided to leave the original washer pump on the right and put the extra washer pump on the left (it doesn't really matter, but just so that it doesn't confuse you).

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[/SIZE][SIZE=-1]Step 5: Now, go to your cabin and feed the wires through the hole. Cut one of the wires leaving about a foot of wire or so. Find a 12V source power wire and splice it into that. Feed the other long wire (you'll need about 8 ft) through the firewall grommet and along the back of the engine (on the firewall), down the passenger side and to the washer pump.

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Step 6: [/SIZE][SIZE=-1]Bolt the washer reservoir back into its original location. [/SIZE][SIZE=-1]Put a plug-type spade on the end of the wire that you fed through the firewall. The spade will fit exactly onto the washer pump terminal (don't know exact size, but it's the spade with the red boot that you can get at Home Depot). Use a shorter piece of wire and connect two spades to it - a plug type spade and a U-shape spade. The plug-type end will go over the remaining terminal on the washer pump, and the other to a ground. Look under your headlight, there is a series of grounds there. I unbolted it and used that as a ground. As you can see, I taped my spade connectors up with electrical tape (the pump on the left).
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Step 7
: Plug the original washer pump tube and harness back. Take the roll of black microtubing and cut about 6 ft of it. Don't worry if you mess up, you have 44 ft left. Connect one end to the washer on the left hand side. Then feed the tubing through one of the holes in the support. Run the tubing under your headlight and straight across the bumper reinforcement. [/SIZE][SIZE=-1]Twist the jet sprayer into the microtubing. [/SIZE][SIZE=-1]Make sure the jet sprayer is pointed directly at the SMIC (or FMIC). [/SIZE][SIZE=-1] Clean the reinforcement and use the Velcro or sticky tape to hold the tubing in place. [/SIZE][SIZE=-1]I taped the tubing to the reinforcement bumper in several areas so that there was little/no chance of it ever falling out. [/SIZE][SIZE=-1]Fill the reservoir with some water so that you can test it out. I found it hard to see AND adjust it because I was by myself. If you have a friend helping you, one person can press the button and one can see the spray pattern better to make adjustments. Test it out and you will see that the SMIC is pretty much soaked after a few seconds.

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Step 8: Make sure you didn't leave any tools in the working area. Install the front bumper back onto the car. Take car for test drive. :)

Conclusions/impressions: In theory, while driving, the water should help cool down the SMIC. Not sure to what extent, but anything would help on a hot day. I also bought a 360[/SIZE][SIZE=-1][/SIZE][SIZE=-1] mister nozzle, but the spray pattern was all wrong and it didn't work that well. I suspect the washer pump doesn't provide enough pressure to create a finer mist. I will update when some testing is done.
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Nice writeup! depending on how my car performs in the summer heat (I've only been turboed since January) I may consider something like this. How does using water for the windshield washers work? I don't even have the washer nozzle holes in my summer hood so it's no biggie if it doesn't clean well, I only use washers in the winter anyway.
 
Kansei said:
How does using water for the windshield washers work? I don't even have the washer nozzle holes in my summer hood so it's no biggie if it doesn't clean well, I only use washers in the winter anyway.

I hardly use my windshield wipers in Cali. i think i filled the washer reservoir once in just under 2 years. anyways, right now, it's just water in there. but i think even using a mixture with windshield washer fluid can help b/c it has alcohol in it (usually methonal or ethanol) it dries faster. so technically if you diluted the mixture, it can aid in evaporation of the water.

What you could do is use a 3 way tee with a turn valve on two of the lines, one to your wiper nozzles and one to your intercooler nozzle. so you can switch back and forth between summer and winter.
 
ya i dunno did this long ago and noticed no diff at all in performance.NONE. not to mention you look pretty dumb when your car is leaking all over the place before a race, especially if you lose. i had 3 nozzles being powered by a larger pump then you have and you would think it would work great, it just doesnt. i dunno maybe we should try checking intake temp diff before and after a soaking. my guess is its next to nothing.
 
Seems like it would be far more effective to use a water / methanol injection setup to really cool things down when the boost is high in hot weather.

is there a DIY solution that can be done cheaply??

$400 for a kit seems a bit steep.
 
hotrodf1 said:
Seems like it would be far more effective to use a water / methanol injection setup to really cool things down when the boost is high in hot weather.

is there a DIY solution that can be done cheaply??

$400 for a kit seems a bit steep.

yeah, i looked that up and didn't find anything cheaper than $350-400
 
could you also just (if you never use the washer fluid ever) hook in your sprayer to the original washer pump?

save you half the trouble and time
 
neox.286 said:
could you also just (if you never use the washer fluid ever) hook in your sprayer to the original washer pump?

save you half the trouble and time
yes you can, but you are stuck never being able to spray your nozzles. which i think is actually a safety thing. if you use just one pump, you are stuck with either spraying your intercooler AND your windshield washer nozzles at the same time OR you can only spray your intercooler and then not spray your nozzles. i thought about this before doing my rigging. also, every time you use your windshield wipers (in the spray mode), your sprayer will go off. unless you hook it up independently to another button.
 
well, the sprayer only goes off if you pull the wiper handle...you can run the wipers without the sprayer

idk, just my oppinion, not necessarily the greatest (as usual lol) =)
 
Why not just drop a few ice cubes in the top of the winshield washer fluid reservois?

IM sure it will cool the liquid down some and spray colder water at the intercooler
 
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