Crazy Idea: Liquid CO2 Intercooler Freeze Spray

[Soul Shinobi]

I've just come up with this. I have no idea how well it will work. I plan to make one, not sure how soon.

The plan is to make an intercooler spray that can be operated by the driver or codriver. The awesomeness comes in the spray's payload: compressed carbon dioxide. When releasing compressed CO2 from a liquid state the expansion of it causes it to cool to below freezing temperature.

I plan to use a CO2 canister I have from a paintball gun and put a valve on the end. From there I have to make something that can attach to that and go to a tube that can take the pressure of the expanding CO2. After that all I need is an appropriate nozzle for delivery.

I don't know if by the end of the releasing whether the CO2 will be a liquid or a gas, but I'm sure it'll be quite cold.


Concerns:

Pressure. The most concerning problem that can occur is that the delivery system will fail. I need to make sure seals are tight but more importantly that the materials I use can even withstand the pressure of the expanding CO2. This is a at home DIY job and I have no numbers to go by, it'll careful trial and error.

Freezing. If you play paintball you know that when playing below 40 degrees F there's a chance of the CO2 canister freezing up.

Let's take a look at this lovely CO2 chart, shall we?



Okay, so the temperature range we'll look at here is between 250 K (-10F, -23C) to 300 K (80F, 27C). That range covers as low as the outside air should go where any of you live (unless you live someplace where people shouldn't be living) to a nice warm 80 degrees F, or 27 C.

I don't know what the fuck a "supercritical" fluid is, but don't worry about it man, because paintball CO2 canister DO fall under that range, but there's no warning about it for paintballers, so I'm not worried.

The pressure range we'll be looking at is between 1 Bar (14.5psi, atmospheric pressure) and 124Bar (1800psi, common compression in a paintball CO2 tank).

So, moving on if we look at the coldest most pressurized area for our purposes, 250 K at 124 Bar, CO2 is still a liquid. Now, the reason it might freeze up and become a solid is because the canister can get MUCH colder when depressurizing. Looking this graph CO2's solid state begins around 220 K (-64F, -53C) and as we know the tank can freeze up under normal use in cooler weather when playing paint ball.

What this equates to in a cooling system that uses continuous streams of CO2 is that you'll only be able to use it fully open, oh let's guess, for 6 to 12 seconds in warm weather and 2 to 5 seconds around freezing temperature. At a time. Once the canister warms back up a bit you can do it again.

The one other concern with freezing it at the end of the spray nozzle. I'll just have to experiment to see what works well.

Corrosion. My final concern is that spraying pure or maybe even liquid CO2 onto an aluminum intercooler might cause corrosion. I have no idea if it will or not, aluminum may not be affected at all.

Cracking. Oh yeah, just thought of this one. Cooling down the intercooler rapidly may cause it to fracture. That would suck, but shouldn't be a problem if the spray starts 6 inches or so from the intercooler, or is spread wide enough.



So, what do you think? Brilliant? Crazy? Stupid? Someone already did it?

[92ss satinsvoice]

you know there are noz kits called intercooler spray kit. basicly what your talkin about. it would work great. that just reminds me now that ive got a front mount im going to make my self a kit like your talkin about.

[tris91ricer]

So people use both -- CO2 and NOS? Will either one give the same result --icing on the fin box?

Jeff wants to put a sprayer on mine, as well, but he said NO2, not CO2. what's the difference?

As far as lines go, some kind of SS braided line would be optimal, methinks.

[92ss satinsvoice]

well im going to keep it simple cause i dont know the science behind those two chemicals. when the molecules expand (when the bottle is being vented) they get really cold. im not sure witch gets colder but they both basicly do the same thing. ones a gas and the other is an element. plus i think no2 if far more explosive then just regular CO2.

it would be cheaper to go with C02 though. got to your pant ball shop to fill your tank. instead of looking for some one who sells no2. i know nos ant cheap.

[dropdfocus]

Yeah, I'm a long time paintball player & those who start into the sport tend to use a "cheap" gun (ie: Spyder, Icon, Tippmann, etc.) which will work off of CO2 unlike high end guns which only work with compressed air.

As stated, cold temps lead to frozen CO2 bottles & if you don't have an anti-siphon installed, you will draw liquid CO2 into the gun.

So, I think you're on to something here. You could actually utilize the solenoids from a PB gun to release the spray to the front of the I/C. From there you could install a momentary switch which will send power to the solenoid instead of the pulse switches that the PB guns use. The on/off rails that the bottles thread into would work as an adapter to go down to braided line then connecting to the I/C spray ring (the type NX or NOS use).

Any further thoughts from anyone?

[jefferson]

The only thing I can think of is you may need more flow rate than the paint ball stuff can handle. I don't know, just a thought.

Jeff

[evolutionmovement]

Neither are elements - they are compounds (1 atom carbon/2 atoms oxygen for CO2 and 2 atoms nitrogen/4 atoms oxygen for NOS since oxygen and nitrogen like to bond in pairs) and both are gases, though they may be stored as a liquid in one of these applications, I don't know. Jeez guys, I almost failed high school chemistry fifteen years ago.

CO2 would probably be cheaper.

[Soul Shinobi]

As stated, cold temps lead to frozen CO2 bottles & if you don't have an anti-siphon installed, you will draw liquid CO2 into the gun.

So, I think you're on to something here. You could actually utilize the solenoids from a PB gun to release the spray to the front of the I/C. From there you could install a momentary switch which will send power to the solenoid instead of the pulse switches that the PB guns use. The on/off rails that the bottles thread into would work as an adapter to go down to braided line then connecting to the I/C spray ring (the type NX or NOS use).

Good idea using a braided line, maybe I could get a used line from a tank relocation kit. That's the kind of on/off valve I was thinking of. As for the rest, I'm not sure what you're saying, probably because I know very little about how a paintball gun actually works. Care to elaborate?

[Soul Shinobi]

Jeff wants to put a sprayer on mine, as well, but he said NO2, not CO2. what's the difference?

Whoah whoah whoah, wait, NO2, or nitrogen dioxide is not only toxic to inhale but it's also considered a pollutant.

[dropdfocus]

As for the rest, I'm not sure what you're saying, probably because I know very little about how a paintball gun actually works. Care to elaborate?

Well, on electronic paintball guns, when you pull the trigger all you are doing is hitting a switch in the trigger frame. So when you do that, it runs through the software on the circuit board. It pulses the electronicly controlled solenoid to open and release the gas/air into the firing chamber. Most of them run off of 9v batteries. You can cheat the voltage from a 12v car battery down to 9v with the proper parts.

If you didn't want to go that route, you could contact any of the aftermarket nitrous companies and purchase a electronic purge valve and have the feed come from the CO2 bottle, through the purge valve, and into some type of spray system (I/C ring or several nozzles all linked together).

[dropdfocus]

Purge valve kits
Prices via Summit Racing.com
Edelbrock: EDL-72176 $105.95
NOS: NOS-16030NOS $115.95
Nitrous Express: NEX-15600 $116.95
ZEX: CCA-82010 $119.95

There's also tons of AN to NPT adapters available too. So making lines fit would not be a problem either.

Intercooler Sprayers
Prices via Summit Racing.com
DEI: DEI-080131 $75.95 (8"x4")
DEI: DEI-080130 $87.95 (16"x5")
DEI: DEI-080134 $159.95 (19"x9")

So far:
Edelbrock purge kit - $105.95
DEI 16x5 I/C sprayer - $87.95
misc. lines & adapters - $45
Total: $238.90 (add $20 for 20oz. CO2 bottle)

OR...

Acutal intercooler sprayer kits:
Nitrous Express: NEX-20000-00 $292.95 (w/o bottle)
Nitrous Express: NEX-20000-05 $387.95 (w/ 5lbs bottle)
Nitrous Express: NEX-20000-05 $416.95 (w/ 10lbs bottle)
NOS: NOS-16034NOS $375.95 (w/ 5lbs bottle)
nitrous bottles start at
$115.95 for 10oz. Sneaky Pete bottle
$139.95 for 2lbs bottle
on up to $249.95 for 10lbs bottle

At your cheapest point (NX kit w/o bottle), the DIY kit saves you $54.05.

[Soul Shinobi]

CO2 tank - $20 (have)
Valve - $10
Some kind of cheap hose and adapters from Home Depot - $15?

That's all I planned on so far We'll see what I can get away with.

[dropdfocus]

You could also purchase a 1/4" air valve which would hold back 300psi. This would give you availability to simply press a button to open the valve and send CO2 to the sprayer mounted over the I/C. I can get the valves at $20 + shipping (my cost / dealer pricing). You'd still need some type of true regulator to take the almost 1,000psi from a full bottle down to an useable 200psi range.

Also, here's a REALLY good site that breaks down all the properties of CO2 and bottle pressures:
http://www.warpig.com/paintball/technic ... mics.shtml

[dscoobydoo]

the result, not very useful as the CO2 loses most of its cold in the steel braided line. by the time the co2 makes it to the sprayer its almost engine temp. If you are going to do it you need a thin line that carry the CO2 at high pressure. I.e. a long paintball gun line. or else the first 3 inches of the line freezes and the rest just carries out air.

also CO2 + Water = Carbonic Acid. It can slowly eat away your intercooler or ur engine bay's paint.

[dropdfocus]

Ok, a very good point. So it almost looks like spending the $375 for the NOS kit is the best option for people then.

Another thought came to mind. The pnuematic air valves also are rated to hold back liquid too. If you could pressurize something holding ice water, the valve openning up would release the ice cold water on to the I/C. Again, just throwing this out on the table for general thought.

[Psychoreo]

you guys are talking about this right? http://www.designengineering.com/produc ... m=sc&cid=1

[Soul Shinobi]

Ok, a very good point. So it almost looks like spending the $375 for the NOS kit is the best option for people then.

Almost, until you realize that most people don't have $375 to blow on something they could have the satisfaction of building themselves for much less.


Did some poking around, a 20oz aluminum CO2 tank can be found for as little as $14. I went to Home Depot and found some braided lines of polyurethane or something like that. I just need to get a valve and some brass adapters on top of that (I already have the CO2 tank) and I can test it out.

[dropdfocus]

I'm just curious how dangerous the output pressure is going to be just trying to use a standard on/off brass valve to control the spray...

And yes, that is pretty much what we are talking about doing. Either making all our own components or half DIY & half purchased pre-made parts.

[rallysam]

I don't know if the system would really be better than a water sprayer in the end. Thing is, you might be able to get CO2 colder than water (if you actually manage to hook up a system that can pipe it without warming it), but H20 has insane specific heat and energy of evaporation, which is just as important. I don't know those parameters for CO2, but hardly anything is as good as water.

Even if CO2 was colder than freezing, and if you had enough on-board to cool the intercooler, and if it was efficient enough to get the intake air that cold too.... is the air STILL going to be that cold after traveling through the throttle body and manifold? I doubt it. So, you might as well use water to do the same thing.

Is there any point to trying? I doubt it, b/c the car probably wouldn't even run right if the air WAS that cold. The car would run like you just started it on a cold morning AND you had a faulty temperature sensor so the mixture wasn't even right for the cold temps.

I think they way to think about intercooling is taking air that's overheated by the turbo and getting it back to room temperature, not super cooling it, in which case water is pretty damn good at its job.

Have I ever tried? No. I could be wrong. Give it a shot. But these are just my thoughts.

[dropdfocus]

Thanks for the input Sam. I've seriously thought about just grabbing the same washer fluid pump my old Chevy truck uses. Very small & compact, but still manages to spray at a pretty good pressure across the windshield. Picking up a spare fluid bottle at my local you-pick-the-parts junk yard would be easy enough.

As for stashing the res. container & the pump in the trunk like the STi does, do they just spray straight water or water mixed with another solution?

[rallysam]

Pretty sure they spray just water. That's what I used, and I left all winter. Still works, so I guess freezing doesn't hurt???

If you rig up a windshield washer system as IC spray, you might think about using nozzles designed for an IC spray instead of windshield nozzle. Subaru dealers can sell you STI ones or you can probably other brands wherever. IC nozzels create a pretty fine mist which is a little better for evaporation. But, anything works - just gotta get water on there

[dropdfocus]

If you rig up a windshield washer system as IC spray, you might think about using nozzles designed for an IC spray instead of windshield nozzle. IC nozzels create a pretty fine mist which is a little better for evaporation.

Ah, good point. Didn't even think about that. Thanks!

[Soul Shinobi]

I may try that nozzle too, so long as it doesn't seem like the CO2 will freeze up at the tip. If all else fails I'll just keep the hosing and nozzle and turn it into a water spray.

[Psychoreo]

Ok, a very good point. So it almost looks like spending the $375 for the NOS kit is the best option for people then.

Almost, until you realize that most people don't have $375 to blow on something they could have the satisfaction of building themselves for much less.


Did some poking around, a 20oz aluminum CO2 tank can be found for as little as $14. I went to Home Depot and found some braided lines of polyurethane or something like that. I just need to get a valve and some brass adapters on top of that (I already have the CO2 tank) and I can test it out.

I was just asking to make sure I had the right idea in my head. If you can build one at home I say go for it, try it out and let us know how it worked!