Okay, here's some info for you on this whole idea. I have a keen interest in science, so I'll give you the straight up skinny, CO2 will NOT work like N20, here's why.
We, as living creatures, bring in oxygen to our lungs, this oxygen is used to burn off our fuel (food and water) to power our our flesh-and-blood bodies As a byproduct, we exhale a gas called carbon dioxide, or CO2 as it's been called here.
Now, cars are a lot like us, they need fuel and oxygen to produce the energy to sling the pistons and make power to move, just like us. You normally wouldn't think of them being "Alive" like we humans, but in reality, they are. You see, none of this is possible without fire, the fire that is burnt from gasoline and air in each cylinder...
Many firefighters and scientist describe fire like a living creature, it breathes, it eats, and will move along any path where there is fuel to burn, it can reproduce. It's life, but not as you know it.
Unlike us, car engines, and specifically, the fire in the cylinders, produces a byproduct in the combustion process, a gass called carbon monoxide, or simply CO.
living creatures give off carbon dioxide, most fires give off carbon monoxide (some give off more than that, depanding on what is burned as fuel). Carbon monoxide is poisonous to humans, however, the human body can tolerate carbon dioxide. Carbon dioxide has two oxygen atoms to every carbon atom, while Carbon Monoxide has only one oxygen atom to every carbon atom. May not sound like much, but it's a major differnce in terms of chemistry.
Injecting co2 will reduce temps, but it will also starve the combustion chambers of oxygen, the carbon atom (and it's strong atomic bond to the oxygen) will not be broken easily by combustion temps. It could be used to deter detonation if used in trace amounts, but any actual "shot" of co2 will just bog your engine. Remember, we can't breathe-in on CO2 alone, and neither can a fire.
So why does N2O, or nitrous oxide, work when co2 doesn't? that's simple, it's because N2O is what's known as an oxidizer.
aside from the one atom of oxygen in each molecule, Nitrous has two aces up it's sleeves: a pair of nitrogen atoms (Nitrogen is what makes things like "fertilizer bombs" work) since it's only oxygen and nitrogen, the atomic bond isn't as strong as it is in CO2. under cylinder temps and pressures, it comes apart at the seams, delivering an oxygen/nitrogen ratio of 1/2 in other words: one part oxygen to two parts "fuel catalyst". When combined with more fuel, the result is a much bigger bang, and co2 simply can't do this. Nitrogen won't work either, not without extra oxygen.
For chilling intercoolers, or Intakes
, CO2 would work great because it's cheaper than N2O, but it will just hinder your engine if shot directly down the Intake
. Too much CO2 = Weak burn.