Home made intercooler water spray

dscoobydoo · Post by **dscoobydoo** » Thu Sep 23, 2004 8:39 pm

Just for shits n giggles, I was cruising the junkyard looking for a tank to use for this project. I figure that it would be better to get a tank just for this, unlike the STI using the washer fluid one.
Well, I pulled a thin, long tank from an 86 626, and took out one of my horns to make it fit. So it sits between the front driver's light and the battery, but fits perfect. I picked up a push button switch which will be mounted just south of the shifter.

The tank came with the pump, so I just ran hose along the fenderwell and up to the back of the intercooler. ( when I go FMIC, I will just move the spray line)

If you go to HOMEDEPOT or another place with sprinkler stuff, you can get the very small spray jets. Two will work, but i am going 4, one on each side. the spray pattern covers the Saab cooler nicely with very little overspray.

I wired up the relay for the switch and TADAAH!

Whole thing cost me about $22

QuickDrive · Post by **QuickDrive** » Thu Sep 23, 2004 8:51 pm

Nice, pix?
Results?

BAC5.2 · Post by **BAC5.2** » Thu Sep 23, 2004 9:13 pm

Vikash made one too, using the washer tank from a BG, which has 2 pumps.

FYI, The STi uses a tank mounted in the trunk, not a split off of the washer tank.

The manual suggests using washer fluid anyway, so it's just as easy to swap a newer BG tank and have it all in one unit.

vrg3 · Post by **vrg3** » Thu Sep 23, 2004 9:21 pm

Cool, man.

I went to Home Depot once looking for the garden sprinkler nozzles and they didn't have anything except the kind that you normally attach to garden hoses. Is it in a section other than the gardening section?

I just have one windshield washer nozzle from a Saturn (so it's kind of misty rather than being a concentrated jet), but I can't tell if it helps or not. Right now I have my boost down really low anyway though.

Where are you going to relocate the horn to?

A bonus with the newer wagon washer tank is that it easily accepts just over a full gallon of fluid, so when I buy a gallon of washer fluid I pour the whole gallon into my car instead of having a little left over to spill out onto my rear carpet.

BAC5.2 · Post by **BAC5.2** » Thu Sep 23, 2004 9:23 pm

But Vikash, how would it ever see your rear carpets?

vrg3 · Post by **vrg3** » Thu Sep 23, 2004 9:39 pm

I used to always fill up the tank and then put the cap on and store the bottle holding the unused portion in one of the rear footwells. The cap is of a cheap design and doesn't seal (that's why they have to put the foil cover over the mouth) so it leaks out onto the carpet.

eastbaysubaru · Post by **eastbaysubaru** » Thu Sep 23, 2004 9:49 pm

FWIW, I've read that the nozzles/sprayers from Home Depot and such don't atomize (?) the water enough to be really effective. This is the article I got it from.

http://www.netcomuk.co.uk/~gavinp/airwater.htm

-Brian

vrg3 · Post by **vrg3** » Thu Sep 23, 2004 9:58 pm

I think a lot of it has to do with the control system... Like he says on that page, you want it to evaporate right away rather than wetting the intercooler. It seems to me that if you can spray in short enough bursts you could get away with poor atomization.

And there's also the issue of how to trigger the spray... You kind of want to predict how useful the spray will be. You have to take into account vehicle speed, intercooler heat soak, boost level, etc...

dscoobydoo · Post by **dscoobydoo** » Fri Sep 24, 2004 5:24 am

OK, I read somewhere that the STI uses a connection right off the washer tank. My mistake if this is not true.

AS for the sprayers, there are light mists and small spray patterns.
You have to look in the sections past the large ground sprinklers. There will be hose and tees and connectors along with the different jets.

As for the spray water, I prefer to use just water, not washer fluid in that water alone has the best cooling properties. That and having the tank up front allows ease for filling, and for wiring and tubing.

The trigger is a manual button down from the armrest for ease of access.

Pics will be posted ina week or so when I get them.

vrg3 · Post by **vrg3** » Fri Sep 24, 2004 5:28 am

I believe the early STis used the washer tank. Somewhere along the line they switched to having a separate reservoir.

I would think washer fluid would cool better than plain water, because it's basically a mixture of methanol and water so it should evaporate faster.

BAC5.2 · Post by **BAC5.2** » Fri Sep 24, 2004 5:47 am

Yea, I'm speaking about the USDM V.8 STi.

Vikash, your backseat is so full of stuff, the fluid would never find its way to the carpet

dzx · Post by **dzx** » Fri Sep 24, 2004 10:50 am

Yeh, your looking for evaporation qualities, not heat capacity. Alcohol would evaporate faster creating a cooler surface. which is why when you a thin film of alcohol on your skin and you blow on it, it feels cooler than blowing on water.

dscoobydoo · Post by **dscoobydoo** » Sat Sep 25, 2004 4:50 am

You guys forget the different properties of the different alcohols. Each mixture has a different evaporation and cooling property. You also have to worry about the effects on the pump, gaskets and tubing.

Yes, if I add alcohol into the mix, it will change the evaporation rate and cooling properties.

That will be part of the equation= figuring out what mix works best.

Too much alcohol will evaporate too fast if the cooler is too hot. The spray pulls the heat from the intercooler by landing, absorbing the heat then evaporating. That is why the finer sprays work better= more surface area.

That is one advantage to just pure water, that and it won't foul up or affect the plumbing or pump. But yes, it will not evaporate as fast.

I plan on starting with pure water and working in a mix, after doing tests. Most washer fluid also has other things in it that will stay behind and leave film on the intercooler. That is what I am trying to avoid.

dzx · Post by **dzx** » Sat Sep 25, 2004 12:38 pm

Right, one alcohol that you could use is isopropyl. Being a polar molecule, it is soluble in water. Hydrogen atoms in water will be attracted to the loan pair of electrons on the alcohol functional group. The more polar a molecule is, the easier it is for water to surround it and isolate individual molecules making it "soluble". If your just doing short bursts with the solution on your intercooler few and far between yes it wouldnt work to well, because the intercooler would be dry inbetween shots. However if your just using it for the quarter mile and not driving with it on all the time I don't really see it using that fluid since a fogger flowing approximately 9 gallons per hour will use about .15 gallons in a one minute quarter mile. Using five foggers each spraying 9 gal per hr would make it .75 gallons for a one min quarter mile. So... a 16 sec quarter mile would use .2 gallons and at a price of about 6 dollars a gallon at menards mixed with some water, its not that much. I wouldnt be too worried about a film so long as its on the outside of the intercooler it should just wash right off.

TurboLegacy · Post by **TurboLegacy** » Sat Oct 09, 2004 5:11 am

couldn't i just take the windshield washer jets right out and attach some jets found in the produce coolers at grocery stores? i hardly ever use my windshield washers anyways. will there be enough pressure in the lines to be effective?

dscoobydoo · Post by **dscoobydoo** » Mon Oct 11, 2004 6:17 am

Yes, you could just re-plumb your washer lines. The jets I used are a fine mist, because this is what I was after. I used two jets, one north and one south. If i run it for 2 seconds, it comes out just about right. The pump on the added tank pushes the right amount of fluid through.

Give me some time and I will post pics and you can either go Ohhh, or go WTF!

But hell, works for me.

TurboLegacy · Post by **TurboLegacy** » Sun Oct 24, 2004 6:27 am

is there noticeable performance gains to the waterspray?

dscoobydoo · Post by **dscoobydoo** » Wed Oct 27, 2004 5:37 pm

As for performance gains, well, it turned cold just after I finished it, so I have not had the right conditions to determine. But, if the STI has one, I would think it would be worthwhile.

anyway, here ( finally) are the pics:

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Home made intercooler water spray

Home made intercooler water spray