How To: Automatic Intercooler Sprayer (boost referenced)

**WolfPlayer** · 01-06-2006, 09:32 PM

Idea: The stock intercooler sprayer is fully manual. I want to have the intercooler sprayer fire automagically without having to press the I/C sprayer button.

Quandry: What should be used as the signal to fire the sprayer? The main options I have seen are Temperature, RPMs, Throttle position, Clutch switch, and Boost (what this article deals with).

- Temperature. This is, by far, the ideal. However, it is the most expensive and the most difficult to implement. Very fast acting adjustable temperature switches are expensive. Furthermore, to use temperature you really need 2 temperature sensors and a controller that computes the difference. Ideally, temperature based intercooler spraying is accomplished via the difference between air entering the intercooler and air exiting the intercooler. This method also requires drilling and tapping the intercooler, etc. For me, this wasn't an option I wanted to pursue (although I have the necessary experience, knowledge and tools to do it).
- RPMs. This method is accomplished by using an RPM trigger to activate the spraying. I am not a fan of this method because I want my intercooler spraying as soon as I hit reasonable boost. I hit 18psi by 2900rpms on my VF39 and there is no way I would setup an RPM trigger for 2900rpms because I hit that during normal part throttle driving.
- Throttle Position. This method is superior to RPMs (IMHO). It's really not a bad way to do things and will accomplish the spraying things down very effectively. However, there is no really easy way to accomplish this. With cars that have throttle plates activated by a true cable (not our drive by wire setups) you can mount a momentary switch at the throttle body that will activate once WOT is reached. This is what is done in a nitrous installation. The only other way to do this is to have something like a UTEC that can monitor throttle position and trigger and external switch/solenoid.
- Clutch Switch. I see only one reason to use this approach which I will get to later. Theoretically, I just don't think this approach makes that much sense. Why would you want to trigger the intercooler sprayer when you are off the throttle with the clutch pressed in? Yea, I understand it accomplishes an automagic spraying. However, you have to remember to turn the activation switch on/off. Moreover, what happens in a high speed run in 4th, 5th or 6th gear when the clutch insn't pressed in? Ok, so what is the main reason to take this approach? Cheap. This is the cheapest automatic spraying method that will get the job done. One thing that I really do like about this method is that it seems like it is a good idea for drag racing. As you are sitting at the tree with the clutch pressed in the sprayer will be firing. That's a good thing.
- Boost. This is one of the best methods when evaluating money invested, time invested, and the actual outcome. This method can cost as little as $20 in parts and will trigger the intercooler sprayer at any pressure set point. Furthermore, even when you are WOT and banging gears, the intercooler sprayer is still spraying due to the factory built-in spray time. So, for a full WOT run it will spray the entire time.

So, on to the install of our automagic intercooler sprayer based on boost reference

Parts
1. Adjustable Normally Open (NO) Pressure Switch. I bought mine from ebay user 'becoool'. They also have a website at Computer Water Cooling, Automotive Water Injection, Aquarium Chillers and Pumps,. Pictures/Price of my switch are here: www.bescaredracing.com - /sti/intercooler/sprayer/auto/sensor/
2. Some small gauge wire (18-22 gauge is fine)
3. 18-22 gauge wire taps (red) (2 for a normal install, 4 for a JDM Auto switch install)
4. Female terminal ends (red) (2 for no toggle, 4 if you use a toggle, 6 for JDM Auto switch install)

Optional Parts
- Toggle Switch (Single pole single throw) to activate the "automagicness". You will want this if you live in an area where the water in the intercooler spray reservoir can freeze or if you think that you might run out of water in your reservoir.

Super Optional Parts
- Instead of using a standard toggle switch use the JDM Auto Intercooler Spray switch for that factory install look

Wiring diagrams:
Stock - http://www.bescaredracing.com/sti/in...gram/stock.JPG
No toggle Switch install - http://www.bescaredracing.com/sti/in...m/notoggle.jpg
Standard Toggle Switch install - http://www.bescaredracing.com/sti/in...ram/toggle.JPG
JDM Auto switch install - http://www.bescaredracing.com/sti/in.../togglejdm.JPG

Directions:
1. Put some food in your belly. I like to heat up some frozen chicken nuggets and put them on little potato rolls. Fire up your garage computer to reference diagrams and crank up the stereo

http://www.bescaredracing.com/sti/in...l/DSC05596.JPG

2. Pop out the switches and blanks. The easiest way to do this is to pull out the coin box and come from underneath. The first time you do this it is very hard. It gets easier the more you do it.
http://www.bescaredracing.com/sti/in...l/DSC05597.JPG
http://www.bescaredracing.com/sti/in...l/DSC05598.JPG

3. For illustration purposes only, these are the two pins that the pressure switch will bridge together. It is these two pins that will fire off the intercooler relay. You can try it yourself. Simply turn the key over to accessories and bridge the two pins with a short piece of wire. The intercooler relay will fire and the sprayer will come on.
http://www.bescaredracing.com/sti/in...l/DSC05600.JPG

4. Remove the extra OEM tape from the wire bundle
http://www.bescaredracing.com/sti/in...l/DSC05601.JPG

5. Add a wire tap to pin #3, yellow wire with red stripe. Depending on your install, this wire will either go to a toggle switch to arm the system or directly to the pressure sensor. Use enough wire to reach your destination. I am using a JDM Auto switch so I only needed a short length to reach the space directly next to the stock switch.
http://www.bescaredracing.com/sti/in...l/DSC05603.JPG

6. Add a wire tap to pin #5, red wire with white stripe. This wire will go to the pressure sensor. Just use a 2-3ft length of wire and you can cut off the rest later.
http://www.bescaredracing.com/sti/in...l/DSC05604.JPG

7. Test your connections. Put the keys in the ignition and turn to accessories. Touch the wire ends together. The intercooler sprayer should fire.
http://www.bescaredracing.com/sti/in...l/DSC05605.JPG

8. If you are not going to use a toggle switch then jump to step 11. To use your toggle switch use the wire you hooked up in step 5 and put that on one prong of your toggle switch. On the other prong hook up a 2-3ft length of wire. This is something like what you will have if you run a simple toggle switch:
http://www.bescaredracing.com/sti/in...l/DSC05612.JPG

I am using the JDM Auto intercooler spray switch so I had to run a crapload of wires. Don't let this picture scare you. I doubt many of you will ever install a JDM switch for this purpose but who knows:
http://www.bescaredracing.com/sti/in...l/DSC05614.JPG
When using the JDM switch, the best way is to just buy another Intercooler Switch harness connector. However, when using various crimp connectors like I did, make sure to use some electrical tape to ensure that everything is bundled nicely to the connector so nothing can come off/out with all the hard launches you do

9. When all is said and done you will have 2 wires not terminated: The wire from step #6 and the wire from step #5 (if you did not install a toggle) or the wire from the toggle (if you installed a toggle).
http://www.bescaredracing.com/sti/in...l/DSC05613.JPG

10. Test your connections. Put the keys in the ignition and turn to accessories. Touch the wire ends together. The intercooler sprayer should fire whenever the toggle is in the correct position.

11. Hook up the pressure sensor. I have a mechanical in-car boost gauge. So, for me, this was super easy. All I did was cut the vacuum line in a good place under the dash and put the pressure sensor in the middle. Very easy.
http://www.bescaredracing.com/sti/in...l/DSC05617.JPG
http://www.bescaredracing.com/sti/in...l/DSC05618.JPG
http://www.bescaredracing.com/sti/in...l/DSC05620.JPG

12. Hook up your remaining connections to the pressure switch. With the switch that I purchased you use the silver prong (common) and the closest gold prong (normally open) as shown in the picture below:
http://www.bescaredracing.com/sti/in...onnections.JPG
The other prong is the normally closed prong. Ignore this terminal. It is unused in this application. When you are done, wrap the switch in some electrical tape to protect the Normally Closed prong from external contact.
http://www.bescaredracing.com/sti/in...l/DSC05622.JPG
http://www.bescaredracing.com/sti/in...l/DSC05626.JPG

For the record, the absolute safest way is to grab the 12V positive from the original stock intercooler spray switch and run it through the toggle and to the normally open terminal on the switch. The silver terminal then gets routed directly back to the original intercooler spray switch. The reason this is the safest is because if you route 12V to the common prong, then the normally closed prong will have that 12V. Is this a big deal? Not really. Just make sure you tape up the switch to ensure that prong doesn't touch a ground anywhere.

13. My finished product
http://www.bescaredracing.com/sti/in...l/DSC05628.JPG
http://www.bescaredracing.com/sti/in...l/DSC05616.JPG
For those that are curious as to what is all the way on the left: That is for my Innovate LC-1 Wideband. The light is the indicator as to the status of the wideband and the button is used for a free-air calculation. After I purchase the XD-1 gauge for the LC-1 Wideband, I will remove that, move both intercooler switches over, and then install the fog lights

That will give me 3 factory switches in that location.

I adjusted the pressure switch to fire when I reached around 12-13lbs of boost. With this particular switch there is a small allen screw that is adjusted using a 5/64 allen wrench. Clockwise raises the pressure. Each half turn is about 2psi. Mine was delivered with around a 6psi setting. I turned it clockwise about 1-1/2 turns.

Notes: This particular pressure switch isn't quiet. I wouldn't call it loud by any means. However, it is important for me to note that I can hear it clicking when the pressure set point is reached. With a 12-13psi set point it really doesn't matter because the exhaust is drowing it out at that point

good luck, have fun
t

LightWerkz · 01-06-2006, 09:40 PM

thanks alot, im going to do this sometime..

esemes · 01-06-2006, 10:14 PM

awesome:::

notes..........

2) pull out the COINBOX, not the ashtray (i think?)

12) which wires go to which prongs, and what's the deal w/ the leftover one??

excuse my ignorance here; im electrical idiota....

great writeup and review. iam DEFINITELY doing this now, thanks to you (and the others authoring the original thinktank thread....

ese

***Datadatum*** · 01-07-2006, 05:41 AM

Wolf - very nice addition to the site. Location bookmarked for upcoming Spring modifications.

**WolfPlayer** · 01-07-2006, 05:48 AM

Quote:

Originally Posted by esemes

2) pull out the COINBOX, not the ashtray (i think?)

12) which wires go to which prongs, and what's the deal w/ the leftover one??

Ese,

2) Good call. It has been changed to coin box.

12) The switch that I used is a very versatile switch. It has pins for BOTH normally open and normally closed. I tested everything with a digital volt meter to determine which connections need to be used. I'll label a closeup and put it up later. However, in the time being ...

http://www.bescaredracing.com/sti/in...r/DSC05339.JPG

In the above picture the silver pin on the bottom at 90deg is always connected. It does't really matter which wire goes where on the switch. Just make sure to hook one of them up to the silver 90deg prong. The other wire goes to the gold prong closest to this silver 90deg prong .... or, to keep it simple, the middle prong. The middle prong is 'normally open' (NO) and closes inside the switch to connect the prongs together once the designated pressure has been reached. The other gold prong is 'normally closed' (NC) and always provides a connection between the prongs EXCEPT when the pressure has been reached.

The way to tell NO from NC is use a voltmeter setup to measure resistance. Touch the voltmeter to the common prong and the prong to be tested. If the resistance is infinite then there is no passing of current and, for all potential purposes, there is no connection between these prongs. If the voltmeter measures resistance (usually very low) then the prongs are connected.

t

TTTT · 01-07-2006, 02:07 PM

Awesome write up Wolf. Hat's off...can we make this a sticky somewhere?

The White Pony · 01-07-2006, 02:56 PM

very good write up. I have been waiting for someone to create a DIY for this mod! Looks great!

**WolfPlayer** · 01-09-2006, 05:29 AM

Updated to reflect that you should use some electrical tape on the pressure switch, etc.

***Nachos Libres*** · 01-09-2006, 06:16 AM

WolfPlayer, I added it to the sticky. I thought you would have already done that.

PSMBoXer · 01-09-2006, 08:18 AM

Well done

01-06-2006, 09:32 PM	#1
WolfPlayer Moderator & ECU Tech Feedback Score: 6 reviews Car: 05 CGM STI My Stuff: Subaru Parts Fav Mod: mo boostaz Location: Fredneck, MD Posts: 4,107 IWSTI Addict since: Jun 2004	Automatic Intercooler Sprayer (boost referenced) Idea: The stock intercooler sprayer is fully manual. I want to have the intercooler sprayer fire automagically without having to press the I/C sprayer button. Quandry: What should be used as the signal to fire the sprayer? The main options I have seen are Temperature, RPMs, Throttle position, Clutch switch, and Boost (what this article deals with). - Temperature. This is, by far, the ideal. However, it is the most expensive and the most difficult to implement. Very fast acting adjustable temperature switches are expensive. Furthermore, to use temperature you really need 2 temperature sensors and a controller that computes the difference. Ideally, temperature based intercooler spraying is accomplished via the difference between air entering the intercooler and air exiting the intercooler. This method also requires drilling and tapping the intercooler, etc. For me, this wasn't an option I wanted to pursue (although I have the necessary experience, knowledge and tools to do it). - RPMs. This method is accomplished by using an RPM trigger to activate the spraying. I am not a fan of this method because I want my intercooler spraying as soon as I hit reasonable boost. I hit 18psi by 2900rpms on my VF39 and there is no way I would setup an RPM trigger for 2900rpms because I hit that during normal part throttle driving. - Throttle Position. This method is superior to RPMs (IMHO). It's really not a bad way to do things and will accomplish the spraying things down very effectively. However, there is no really easy way to accomplish this. With cars that have throttle plates activated by a true cable (not our drive by wire setups) you can mount a momentary switch at the throttle body that will activate once WOT is reached. This is what is done in a nitrous installation. The only other way to do this is to have something like a UTEC that can monitor throttle position and trigger and external switch/solenoid. - Clutch Switch. I see only one reason to use this approach which I will get to later. Theoretically, I just don't think this approach makes that much sense. Why would you want to trigger the intercooler sprayer when you are off the throttle with the clutch pressed in? Yea, I understand it accomplishes an automagic spraying. However, you have to remember to turn the activation switch on/off. Moreover, what happens in a high speed run in 4th, 5th or 6th gear when the clutch insn't pressed in? Ok, so what is the main reason to take this approach? Cheap. This is the cheapest automatic spraying method that will get the job done. One thing that I really do like about this method is that it seems like it is a good idea for drag racing. As you are sitting at the tree with the clutch pressed in the sprayer will be firing. That's a good thing. - Boost. This is one of the best methods when evaluating money invested, time invested, and the actual outcome. This method can cost as little as $20 in parts and will trigger the intercooler sprayer at any pressure set point. Furthermore, even when you are WOT and banging gears, the intercooler sprayer is still spraying due to the factory built-in spray time. So, for a full WOT run it will spray the entire time. So, on to the install of our automagic intercooler sprayer based on boost reference Parts 1. Adjustable Normally Open (NO) Pressure Switch. I bought mine from ebay user 'becoool'. They also have a website at Computer Water Cooling, Automotive Water Injection, Aquarium Chillers and Pumps,. Pictures/Price of my switch are here: www.bescaredracing.com - /sti/intercooler/sprayer/auto/sensor/ 2. Some small gauge wire (18-22 gauge is fine) 3. 18-22 gauge wire taps (red) (2 for a normal install, 4 for a JDM Auto switch install) 4. Female terminal ends (red) (2 for no toggle, 4 if you use a toggle, 6 for JDM Auto switch install) Optional Parts - Toggle Switch (Single pole single throw) to activate the "automagicness". You will want this if you live in an area where the water in the intercooler spray reservoir can freeze or if you think that you might run out of water in your reservoir. Super Optional Parts - Instead of using a standard toggle switch use the JDM Auto Intercooler Spray switch for that factory install look Wiring diagrams: Stock - http://www.bescaredracing.com/sti/in...gram/stock.JPG No toggle Switch install - http://www.bescaredracing.com/sti/in...m/notoggle.jpg Standard Toggle Switch install - http://www.bescaredracing.com/sti/in...ram/toggle.JPG JDM Auto switch install - http://www.bescaredracing.com/sti/in.../togglejdm.JPG Directions: 1. Put some food in your belly. I like to heat up some frozen chicken nuggets and put them on little potato rolls. Fire up your garage computer to reference diagrams and crank up the stereo http://www.bescaredracing.com/sti/in...l/DSC05596.JPG 2. Pop out the switches and blanks. The easiest way to do this is to pull out the coin box and come from underneath. The first time you do this it is very hard. It gets easier the more you do it. http://www.bescaredracing.com/sti/in...l/DSC05597.JPG http://www.bescaredracing.com/sti/in...l/DSC05598.JPG 3. For illustration purposes only, these are the two pins that the pressure switch will bridge together. It is these two pins that will fire off the intercooler relay. You can try it yourself. Simply turn the key over to accessories and bridge the two pins with a short piece of wire. The intercooler relay will fire and the sprayer will come on. http://www.bescaredracing.com/sti/in...l/DSC05600.JPG 4. Remove the extra OEM tape from the wire bundle http://www.bescaredracing.com/sti/in...l/DSC05601.JPG 5. Add a wire tap to pin #3, yellow wire with red stripe. Depending on your install, this wire will either go to a toggle switch to arm the system or directly to the pressure sensor. Use enough wire to reach your destination. I am using a JDM Auto switch so I only needed a short length to reach the space directly next to the stock switch. http://www.bescaredracing.com/sti/in...l/DSC05603.JPG 6. Add a wire tap to pin #5, red wire with white stripe. This wire will go to the pressure sensor. Just use a 2-3ft length of wire and you can cut off the rest later. http://www.bescaredracing.com/sti/in...l/DSC05604.JPG 7. Test your connections. Put the keys in the ignition and turn to accessories. Touch the wire ends together. The intercooler sprayer should fire. http://www.bescaredracing.com/sti/in...l/DSC05605.JPG 8. If you are not going to use a toggle switch then jump to step 11. To use your toggle switch use the wire you hooked up in step 5 and put that on one prong of your toggle switch. On the other prong hook up a 2-3ft length of wire. This is something like what you will have if you run a simple toggle switch: http://www.bescaredracing.com/sti/in...l/DSC05612.JPG I am using the JDM Auto intercooler spray switch so I had to run a crapload of wires. Don't let this picture scare you. I doubt many of you will ever install a JDM switch for this purpose but who knows: http://www.bescaredracing.com/sti/in...l/DSC05614.JPG When using the JDM switch, the best way is to just buy another Intercooler Switch harness connector. However, when using various crimp connectors like I did, make sure to use some electrical tape to ensure that everything is bundled nicely to the connector so nothing can come off/out with all the hard launches you do 9. When all is said and done you will have 2 wires not terminated: The wire from step #6 and the wire from step #5 (if you did not install a toggle) or the wire from the toggle (if you installed a toggle). http://www.bescaredracing.com/sti/in...l/DSC05613.JPG 10. Test your connections. Put the keys in the ignition and turn to accessories. Touch the wire ends together. The intercooler sprayer should fire whenever the toggle is in the correct position. 11. Hook up the pressure sensor. I have a mechanical in-car boost gauge. So, for me, this was super easy. All I did was cut the vacuum line in a good place under the dash and put the pressure sensor in the middle. Very easy. http://www.bescaredracing.com/sti/in...l/DSC05617.JPG http://www.bescaredracing.com/sti/in...l/DSC05618.JPG http://www.bescaredracing.com/sti/in...l/DSC05620.JPG 12. Hook up your remaining connections to the pressure switch. With the switch that I purchased you use the silver prong (common) and the closest gold prong (normally open) as shown in the picture below: http://www.bescaredracing.com/sti/in...onnections.JPG The other prong is the normally closed prong. Ignore this terminal. It is unused in this application. When you are done, wrap the switch in some electrical tape to protect the Normally Closed prong from external contact. http://www.bescaredracing.com/sti/in...l/DSC05622.JPG http://www.bescaredracing.com/sti/in...l/DSC05626.JPG For the record, the absolute safest way is to grab the 12V positive from the original stock intercooler spray switch and run it through the toggle and to the normally open terminal on the switch. The silver terminal then gets routed directly back to the original intercooler spray switch. The reason this is the safest is because if you route 12V to the common prong, then the normally closed prong will have that 12V. Is this a big deal? Not really. Just make sure you tape up the switch to ensure that prong doesn't touch a ground anywhere. 13. My finished product http://www.bescaredracing.com/sti/in...l/DSC05628.JPG http://www.bescaredracing.com/sti/in...l/DSC05616.JPG For those that are curious as to what is all the way on the left: That is for my Innovate LC-1 Wideband. The light is the indicator as to the status of the wideband and the button is used for a free-air calculation. After I purchase the XD-1 gauge for the LC-1 Wideband, I will remove that, move both intercooler switches over, and then install the fog lights That will give me 3 factory switches in that location. I adjusted the pressure switch to fire when I reached around 12-13lbs of boost. With this particular switch there is a small allen screw that is adjusted using a 5/64 allen wrench. Clockwise raises the pressure. Each half turn is about 2psi. Mine was delivered with around a 6psi setting. I turned it clockwise about 1-1/2 turns. Notes: This particular pressure switch isn't quiet. I wouldn't call it loud by any means. However, it is important for me to note that I can hear it clicking when the pressure set point is reached. With a 12-13psi set point it really doesn't matter because the exhaust is drowing it out at that point good luck, have fun t Last edited by Wes; 10-31-2008 at 09:15 AM..

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01-06-2006, 09:40 PM	#2
LightWerkz STI Master Feedback Score: 78 reviews Car: E46 M3 My Stuff: Subaru Parts Fav Mod: ZCP Wheels Location: Clifton Posts: 7,484 IWSTI Addict since: Aug 2005	thanks alot, im going to do this sometime..

01-06-2006, 10:14 PM	#3
esemes S204 Racer Feedback Score: 12 reviews Car: 996TT Location: clearh²o, FL Posts: 4,755 IWSTI Addict since: Jul 2004	awesome::: notes.......... 2) pull out the COINBOX, not the ashtray (i think?) 12) which wires go to which prongs, and what's the deal w/ the leftover one?? excuse my ignorance here; im electrical idiota.... great writeup and review. iam DEFINITELY doing this now, thanks to you (and the others authoring the original thinktank thread.... ese

01-07-2006, 05:41 AM	#4
*Datadatum* Visiting NASIOC Timeout Feedback Score: 2 reviews Car: 05 STi + 08 OBXT My Stuff: Subaru Parts Fav Mod: baby seats! Location: Jacksonville, FL Posts: 7,667 IWSTI Addict since: May 2004	Wolf - very nice addition to the site. Location bookmarked for upcoming Spring modifications.

01-07-2006, 02:07 PM	#6
TTTT STI Driver Feedback Score: 1 reviews Car: 04 Blue STI Fav Mod: STI Seatbelt Pads :-) Location: Poughkeepsie, NY Posts: 222 IWSTI Addict since: Apr 2005	Awesome write up Wolf. Hat's off...can we make this a sticky somewhere?

01-07-2006, 02:56 PM	#7
The White Pony Professional STI Racer Feedback Score: 5 reviews Car: 06 White STi Location: Long Island, New York Posts: 746 IWSTI Addict since: Nov 2005	very good write up. I have been waiting for someone to create a DIY for this mod! Looks great!

01-09-2006, 05:29 AM	#8
WolfPlayer Moderator & ECU Tech Feedback Score: 6 reviews Car: 05 CGM STI My Stuff: Subaru Parts Fav Mod: mo boostaz Location: Fredneck, MD Posts: 4,107 IWSTI Addict since: Jun 2004	Updated to reflect that you should use some electrical tape on the pressure switch, etc.

01-09-2006, 06:16 AM	#9
*Nachos Libres* Platinum Member Feedback Score: 0 reviews Car: 2005 Mazda 6 My Stuff: Subaru Parts Fav Mod: Car Seat Location: Tyler, Texas Posts: 9,284 IWSTI Addict since: Jul 2005	WolfPlayer, I added it to the sticky. I thought you would have already done that.

01-09-2006, 08:18 AM	#10
PSMBoXer Professional STI Driver Feedback Score: 4 reviews Car: Silver 09 WRX Posts: 491 IWSTI Addict since: Jun 2005	Well done