This is the list of parts you need to make a high quality, low cost intercooler water sprayer kit.
DIY Intercooler Water Sprayer – The Parts
These parts are essential. Listed in order from water tank to nozzles. Numbers correspond to this diagram
To tee into the washer jet line just after the windscreen washer bottle. ebay
Using the washer tank is good because they usually have a big capacity and a level sensor. Plus you don’t have to install a tank!
You may find that the washer tank is too small for you later, in which case you can use a hose joiner to join back together they hose you cut to insert this t-piece. Easy.
2.Pump Silicone Hose
To connect the washer tank to the pump. ebay
Silicone because you need something flexible to give you maximum options on mounting location of the pump. We mount the pump in the wheel arch next to the washer tank, this leads to pretty tight corners in the hose. The rigid plastic hose we use in the rest of the system can not be used here, it is not flexible enough.
3.Pump Fittings & Adapter
To convert the fitting on the water pump to a barb, 6mm (pump inlet). ebay
To convert the water pump fitting to push fitting, 1/2 BSP to 6mm (pump outlet). ebay
From this point until the water nozzles we use push fittings for all water line connections. Super easy to connect, super fast to connect and super reliable.
A minimum of 30psi. Volume is not so important, we will not be flooding the intercooler. ebay
The diaphragm pump should be mounted slightly lower than the tank. 6mm fittings if possible.
There are intercooler water spray kits on the market that use washer jet pumps. These are not ideal and we do not recommend them at all for a few reasons.
One, in our experience the pumps are super sensitive on mounting location and orientation. If they are not mounted below the tank and if they are not orientated properly they will not flow.
Second, they do not keep line pressure.
Diaphragm pumps are excellent because they will constantly monitor line pressure and when it drops below a threshold will activate to build back up pressure. We need constant pressure in the line so when the jet is activated we get atomised flow immediately, we do not want to wait for flow to start or for flow to start as a dribble because the solenoid could switch off before full pressure is reached.
Diaphragm pumps can also supply high pressures, 30 psi is the minimum but up to 60,70 PSI+ is better. The water needs to be misted before it hits the intercooler.
6mm (external diameter) rigid plastic hose from your local garden centre. In the sprinkler section. It is usually very cheap, I don’t think it will be more expensive than a pound a meter and probably much less. Although it is a rigid plastic hose it is quite flexible and should let you feed it from the pump to the jets. This hose will push fit into our fittings making installation super easy and super reliable.
Mounted before the solenoid switch. ebay Push fit fittings, 6mm diameter.
We need to keep the solenoid and nozzles clean for reliability. The orifices in the nozzles are less than a mm in diameter, any bit of gravel, sand, stone, dirt could block the nozzles.
1/8 female fitting. Directional. 12v.
Important. These solenoids have a polarity. They will appear to work regardless of how they are wired but they will only work correctly ie seal, if the polarity is correct.
They are also directional, if your solenoid is leaking, 95 times out of a 100 its because it is set up backwards. They will only seal water flow if they are the right way round.
More information on solenoid valves can be found here
Convert the solenoid fitting to push fittings. 1/8 to 6mm. ebay
9.Misting Nozzles & Accessories
0.6mm is good. The smaller they are, the more unreliable they are, 0.6mm a good compromise ebay
T-Pieces to mount the nozzles. ebay Again, all push fittings makes setting up the nozzles a cinch.
90 Degree fitting to end the hose with a spray nozzle ebay At the end of the hose we just need one 90 degree fitting for the nozzle.
Again, there are intercooler water sprayer kits on the market that use washer jets for a windscreen or headlight. They may look they give a good spray but they don’t. They flow too much water and they do not atomise the water into a mist and they are not designed to work at such high pressures.
We do not need and do not want to bath the intercooler in water, we want to get as thin as possible film on the intercooler. We want the water to be able to vaporise of the intercooler metal as easily as possible. Water sitting on the intercooler will get warm and linger in the intercooler fins reducing the effectiveness of the water. We want to get a mist of water into the intercooler, let it evaporate (the evaporation process is where the heat gets sucked out of the intercooler) as quickly as possible, within a second or two and then spray again.
The nozzles/jets linked to here are designed to work at high pressures and atomise the water, not spray it.
We have run into issues using nozzles with small orifices like 0.3mm, they seem to block if you are using hard water. The 0.6mm orifice solved these problems for us and still atomised the water into a mist.
If you are not going to use your windscreen washer tank, you need an external tank. 70 litres probably a bit much but you get the idea. ebay
If you don’t want to use a switch, you’ll need an intercooler spray controller to spray the intercooler for you automatically. Adjusting the duration of spray and time between sprays can save you a tonne of water not to mention giving better performance with no mental effort. MoviChip
Intercooler Water Sprayer Summary
This set up makes life super easy and the system reliable. The fittings and the push type, easy to hook up and reliable for high pressures.
The hose used in the system is also very cheap but designed for high pressure use.
You can customise the system to include as many nozzles as you want, super easy to add or remove nozzles.
Impossible to say how long the water will last, it depends on how many nozzles you are using and how often you spray your intercooler, you’ll have to do some tests.