CO2 or nitrous spray bar

[Lexstang]

Just curious but if you wanted to put a spray bar on an intercooler heat exchanger would CO2 or nitrous be more efficient at cooling. I know CO2 cheaper but wondered what is coldest when it changes from liquid to a gas.

[Rob]

Im not sure about co2 but i believe the nitrous is around -120 when it changes over.

[Jeff88coupe]

Hold on..let me blow the dust off my chemistry degree.

With a bit of help from google.

The boiling point for N20 is -127 F, for C02 it's -109 F

So it's pretty damm close to being the same temp for either. I would also use the longest spraybar possible. You want it to cover the most area possible of the intercooler so that it has the best cooling results. Which is cheaper to buy also...I know N20 is ~$4/lb...not sure on liquid CO2.

[Kevin Doe]

Here is how I think about it. How stupid would it be to have all the eqipment to make 100 whp, and instead spray it on your intercooler and only make like 10 hp.

If you're gonna spray something cold on your intercooler use C02 (just make sure its not gonan make way into the air filter/turbo. Otherwise you just ruined your advantage of colder air.

If you're gonna go with nitrous, you'd better spray it on the inside.

Anotehr alternative (which I'd recommend it meth/water injection). I successfully ran 28 psi with water/meth injection on pump gas.

[Lexstang]

My theoretical intention was 2 10lb tanks. One for the spray bar and one for power. That way the pressure would still be controllable in the engine injection bottle. Since the boiling point is a little lower for the nitrous I'd just use one of the double bottle brackets. But for me this is theoretical.

[Mista Bone]

Hold on..let me blow the dust off my chemistry degree.

With a bit of help from google.

The boiling point for N20 is -127 F, for C02 it's -109 F

So it's pretty damm close to being the same temp for either. I would also use the longest spraybar possible. You want it to cover the most area possible of the intercooler so that it has the best cooling results. Which is cheaper to buy also...I know N20 is ~$4/lb...not sure on liquid CO2.

Not only the boiling point Jeff, but how much latent heat (BTU) is needed to convert from liquid to gas? 18 degree difference in boiling point might be offset by the higher latent heat propeties of the CO2.

Sorta like running alky and the blower coming back frosted up :)

[Mista Bone]

N2O info

http://encyclopedia.airliquide.com/Encyclopedia.asp?GasID=55

Boiling point (1.013 bar) : -88.5 °C
Latent heat of vaporization (1.013 bar at boiling point) : 376.14 kJ/kg or 161.71 Btu/lb

Vapor pressure (at 20 °C or 68 °F) : 58.5 bar


CO2 info

http://encyclopedia.airliquide.com/Encyclopedia.asp?GasID=26

Boiling point (Sublimation) : -78.5 °C
Latent heat of vaporization (1.013 bar at boiling point) : 571.08 kJ/kg or 245.52 Btu/lb
Vapor pressure (at 20 °C or 68 °F) : 58.5 bar

Roughly 1.5 times the enegry needed (heat) to convert the CO2 over than the N2O. That cooling effect is what your after.

[Lexstang]

nifty if I only had a power adder, this would be useful :)

[zippy94]

I think Kevin Doe Said it best, Spray it down it's throat. You will see better results. Spray a 35-50 dry. And watch how cool your air temps drop and mor POWER!! The cat will make.