Cold Air Intake
Cold Air Intake
Maybe someone that knows more about cars (specifically engines) can share some knowledge with me. Ok, so...Cold air is more dense than hot air. So the colder the air getting to the engine, the better. So why does no one create some sort of intake employing dry ice (or some other cold substance), or something such as the "SuperCooler" system on the 2005 F-150 Lighting Concept (http://bradbarnett.net/mustangs/wall...cept/index.htm)? Or do people already do such things, and I'm just not aware of it. Or am I completely missing something which makes this unfeasible?
Joined: August 23, 2004
Posts: 3,599
Likes: 3
From: Bay Area, California
The way that I see it (and please don't quote my stupidity) is that cooling the air after it gets into the intake is a bit of a lost cause. From the way I see it a certain cfm will be traveling through the intake at a given RPM. Regardless of wheel speed the intake will always be sucking air in and there will never be a ram air effect to the point where air is being pushed, rather than pulled in.
Because of that changing the density of the air once it's already in the intake is throwing ice on a fire. First off it takes immense amounts of energy (or lack there of) to cool something down. There really isn't enough time to cool the air down efficiently between the filter and the valves. Secondly cooling the air may change its density, but there is still the same amount of air coming through the intake. Where I could be wrong in this, is that the cold air could cause more vacuum allowing more cfm (which would shrink to approximately "normal" volume as non cooled air if not cooled) to flow through the intake into the cylinders, allowing the same volume, only with more oxygen-rich air to burn.
I was really dabling with the idea of figuring out a way to run refrigerant lines through my stock intake tube before the throttle body, but after a lot of thought and no progress in sight I set the plan aside since it would probably also wreak havoc on the MAF since the air is measured before the cooling (which wouldn't be very controlled) was employed. Basically my thought process had a slew of foreseeable problems that were not worth tackling.
If you decide to pursue this please keep me updated, but I'm sure if it would get some free power it would be happening in the real world by now.
Because of that changing the density of the air once it's already in the intake is throwing ice on a fire. First off it takes immense amounts of energy (or lack there of) to cool something down. There really isn't enough time to cool the air down efficiently between the filter and the valves. Secondly cooling the air may change its density, but there is still the same amount of air coming through the intake. Where I could be wrong in this, is that the cold air could cause more vacuum allowing more cfm (which would shrink to approximately "normal" volume as non cooled air if not cooled) to flow through the intake into the cylinders, allowing the same volume, only with more oxygen-rich air to burn.
I was really dabling with the idea of figuring out a way to run refrigerant lines through my stock intake tube before the throttle body, but after a lot of thought and no progress in sight I set the plan aside since it would probably also wreak havoc on the MAF since the air is measured before the cooling (which wouldn't be very controlled) was employed. Basically my thought process had a slew of foreseeable problems that were not worth tackling.
If you decide to pursue this please keep me updated, but I'm sure if it would get some free power it would be happening in the real world by now.
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Joined: September 16, 2009
Posts: 3,381
Likes: 125
From: Clinton Tennessee
Well Sebastian, i have thought about a big box of dry ice to cool the air also. Like Peter said, there is so much air being sucked into the engine it would be a lost cause. I remember reading (many years ago) about a 'Indy type car' using dry ice to improve performance. It was just too much extra work for such a small performance gain, they stopped the experiment.
Because of that changing the density of the air once it's already in the intake is throwing ice on a fire. First off it takes immense amounts of energy (or lack there of) to cool something down. There really isn't enough time to cool the air down efficiently between the filter and the valves. Secondly cooling the air may change its density, but there is still the same amount of air coming through the intake. Where I could be wrong in this, is that the cold air could cause more vacuum allowing more cfm (which would shrink to approximately "normal" volume as non cooled air if not cooled) to flow through the intake into the cylinders, allowing the same volume, only with more oxygen-rich air to burn.
I was really dabling with the idea of figuring out a way to run refrigerant lines through my stock intake tube before the throttle body, but after a lot of thought and no progress in sight I set the plan aside since it would probably also wreak havoc on the MAF since the air is measured before the cooling (which wouldn't be very controlled) was employed. Basically my thought process had a slew of foreseeable problems that were not worth tackling.
I was really dabling with the idea of figuring out a way to run refrigerant lines through my stock intake tube before the throttle body, but after a lot of thought and no progress in sight I set the plan aside since it would probably also wreak havoc on the MAF since the air is measured before the cooling (which wouldn't be very controlled) was employed. Basically my thought process had a slew of foreseeable problems that were not worth tackling.

Well Sebastian, i have thought about a big box of dry ice to cool the air also. Like Peter said, there is so much air being sucked into the engine it would be a lost cause. I remember reading (many years ago) about a 'Indy type car' using dry ice to improve performance. It was just too much extra work for such a small performance gain, they stopped the experiment.
Nope.
I just remembered seeing it reviewed in Turbo magazine when it first came out some years back. It was tested on a turbocharged GTI or Jetta IIRC. It did improve the numbers. They were using the intake cooler and the intercooler sprayer. On FI cars on the strip, they tend to spray nitrous over the intercooler to freeze it up before a pass, but you know how much n2o cost. CO2 is waaaaaay cheaper.
I just remembered seeing it reviewed in Turbo magazine when it first came out some years back. It was tested on a turbocharged GTI or Jetta IIRC. It did improve the numbers. They were using the intake cooler and the intercooler sprayer. On FI cars on the strip, they tend to spray nitrous over the intercooler to freeze it up before a pass, but you know how much n2o cost. CO2 is waaaaaay cheaper.
The only other cheaper alternative(s) would be water/methanol injection.
Joined: August 23, 2004
Posts: 3,599
Likes: 3
From: Bay Area, California
One thing I could see being helpful, would be to cool the intake somehow. Even though you don't really have enough time to cool the air, it doesn't make sense that the engine itself is preheating it... Maybe a completely separate cooling system for just the intake?
Well I didn't mean constantly driving around with dry ice. I really just meant for a day at the drag strip, and things like that. I've seen people put bags of ice on their engine in between runs, and just kinda got the idea from that. I'm no automotive genius, in fact far from it...just always lookin' to learn more about cars. I've heard of water/methane injection, but never really looked into it's purpose. I guess I'll have to look into it.
Water/methane injection is the most practicle way to get really useful humid "wet" air induction. I don't know if you've ever driven a carborated car on a cool, damp fall day, but that's where a cold air kit really shines (imo anyway). The other alternative is to throw some ice on the intake.
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