a/c intake cooling

[coos]

I have been toying with this for a while. While the a/c is running, everyone knows that the car loses horsepower. What i want to try and do is compensate for this lost of horsepower, by using that a/c to cool the intake charge. What I was thinking was running the low side a/c lines through the upper intercooler piping thus during a/c operations lowering the air temp, thus raiseing the density of the air= more horsepower. And it will only happen during a/c operation so during racing there will be no effect because the a/c is off. What do you guy's think?

 

[the_mork]

You could have it shut down once you went past your launch rpm but it doesn't work.

When I had a question about air conditioning I was told that it wasn't allowed at the track because it is a safety issue.

You also will never be able to cool enough air volume to matter.

 

[DSMTriad]

You could have it shut down once you went past your launch rpm but it doesn't work.

When I had a question about air conditioning I was told that it wasn't allowed at the track because it is a safety issue.

You also will never be able to cool enough air volume to matter.

I guess you have a point

 

[PieEyedPiper]

I thought similarly when I first got my car. I was always daydreaming about how to utilize the A/C for cooler intake charge.
In the end it became obviously apparent that it would never work for that function and be a massive waste of time and money. However, I did envision a working setup that will cool the IC after a a good lap.

It's fun to think about these kinds of things, just know what's practical and not.

 

[Join]

You could have it shut down once you went past your launch rpm but it doesn't work.

Yeah, but we want the cooling effect at high loads, so when disableing it then there is np use of it.

You also will never be able to cool enough air volume to matter.

That was my conclusion from my research tonight.. Never, is a strong word, but I dont want a trailer behind with a compressor to cool things efficient enough...

It's fun to think about these kinds of things, just know what's practical and not.

Mind the brain..


So, I'll have to find a new crazy plan for charge air cooling!

 

[Join]

I just don't like it being crank driven.

If it's more efficient then the loss, it's no problem. People use compressors that are crank-driven..

In this case.. I have not made the scientific math... But $$$ is better on a IC, I think.

 

[97GSTAUTO]

i thought i was crazy for thinking that. But if it was really beneficial then I think every one would be doing it. Keep in mind that using the ac compressor requires the crank and the engine runs hotter when its in use hence why the fan comes on.

But let me know if it works well for you.

we are getting somewhere. Has anyone thought that maybe the extra power you will actually gain from cooler intake temps will be lost in driving the compressor for the a/c unit

 

[JusMX141]

Keep in mind that using the ac compressor requires the crank and the engine runs hotter when its in use hence why the fan comes on.

This is 50% true.

The engine does get hotter during idle because of the increased load that turning the a/c compressor adds, but the main reason the fan runs is to pull air across the a/c condenser while the car isn't moving. If the condenser gets too hot, the air coming out of the dash will warm up drastically.

If the fan didn't run, while you were sitting in traffic on your way to work the air coming out of the dash would always be hot!

 

[DSMTriad]

This is 50% true.

The engine does get hotter during idle because of the increased load that turning the a/c compressor adds, but the main reason the fan runs is to pull air across the a/c condenser while the car isn't moving. If the condenser gets too hot, the air coming out of the dash will warm up drastically.

If the fan didn't run, while you were sitting in traffic on your way to work the air coming out of the dash would always be hot!

Yeah what he said . I stand to be corrected.

 

[HIGHPSI4]

First off, there is no free lunch. Your set up will pull power from the engine to 'cool' the air charge. The reason you do not hear a lot about it is that it is very expensive to get it to work. There are cheaper ways to get power than running the air charge through an a/c heat exchanger.

 

[andy4g63]

That is nonsense/the whole idea/. Installing CAI, or Water-meth injection, would be much more beneficial and easy. With the BIG FMIC and keeping AC/condenser core in front of radiator/, your car most likely will be overheating in the hot summer months.

 

[motomattxxx]

The compressor will explode above 5000 rpm or so.

 

[Defiant]

If you have found any threads here, I will be happy if you post them..

Your undies should be a swamp by now.

 

[Join]

Your undies should be a swamp by now.

Thanks! Now even I was able to find the tread!

Defiant

 

[DarkStarMenace]

Since we have a lot of talkers and nobody with any experience in the matter, and since I have had this same idea since I got my car back in 2004, I am gonna build this kit.
From this entire discussion, nobody seems to understand how the AC system works. They may know the components but lack the knowledge of their intent. I'm not trying to bash anyone. Most of the comments here are theories against it, we all know theories are not truth, just ideas from facts and opinions.
My intentions of this system are purely for single runs. If an evaporator core can reach 35 degrees Fahrenheit, and you span that core over 3 feet of charge piping, you will see a dramatic drop in intake temps. Charging the AC system while driving would be useless due to load on engine, which will affect boost and gaining enough power to justify it. So my intentions are only for single runs.
Meth/water injections do have benefits over this. Only benefit I could see would be the octane boost. Air/water intercoolers lack the capability of reaching the temps an AC system could achieve.
So I'm building my car and have time to play with this idea and see if there are benefits. As for the cost side of this, if you know what you're doing then cost would be low as long as you still have an existing system. It would be more expensive if you were starting from scratch. I'll keep posting my work here.

 

[Defiant]

We'll never hear another word from you about it, is my bet.

 

[97GSTAUTO]

. Back from the dead. I 2nd that bet. Its a waste of time. Not gonna work. You will loose more power driving the compressor than you are going to gain in hp. Nothing beats an intercooler. Its a pretty simple install.

 

[Join]

Hi!

Are you able to calculate the amount of power needed to cool X amount of charge air 100*C to zero degrees, so we can get a image of the size of compressor needed for this job?

 

[DarkStarMenace]

But I never said I was driving the compressor while I'm trying to make the most power. Do a full load on the compressor, then turn off and do a run. And I would be installing an intercooler but modified for AC plumbing. Since I know nobody is gonna bet, once the point in the statement of a bet.
To join,
I know the charge is not gonna reach 0*, but I think it'll get down pretty close. As far as X amount of power to cool. This system would be utilizing the exisitng AC system and adding more lbs to the cover the intercooler. If the interior can get to 50* F with a tiny evaporator, increasing the quantity of R134 and cooling surface should get my temps down pretty darn close.

. Back from the dead. I 2nd that bet. Its a waste of time. Not gonna work. You will loose more power driving the compressor than you are going to gain in hp. Nothing beats an intercooler. Its a pretty simple install.

 

[the_mork]

How much air do you think goes into your engine in a few seconds? I can assure you it is way more air than is in your interior.

 

[Join]

How much air do you think goes into your engine in a few seconds? I can assure you it is way more air than is in your interior.

That's why I wanted to know the actual need of energy to cool the charge. And, knowin that, how fast will the cooling medium heat up on a run, according to his idea?

I want to see some math on this!

Also, you can calculate how much time the charge air gets to cool at X time in the evaporator.

At 7500rpm, it's 15000liters of air a minute, and 250liters a second? This is with no boost.

 

[the_mork]

Those numbers mean nothing without knowing temp, intercooler pipe interior pressure, and engine VE.

We can pick an arbitrary number such as 34lbs/min that you might see from a mildly modified car in its upper power band on a 3rd gear pull.

You will not be able to cool that much air to any noticeable level with a car air conditioner when you have a high velocity charge moving through your pipes. Then on top of that you are using energy to cool that charge which is draining power from your engine. Cooling the charge before a run is not an option because the cooled charge is sucked up by the engine and then charge piping will heat soak within moments even at the line.

It isn't feasible and you don't need an equation to understand that.

 

[Reject]

Just a thought here...

What if instead of removing the AC, it could be repurposed? What if instead of removing all the lines and such, they were rerouted to work in conjunction with the IC air ducts and/Air Intake ducts to cool the temperature of the air entering the manifold?

I was reading an article that suggested that a 30deg temperature drop in the air being pushed in to the cylinders could yeild as much as a 6% horsepower gain (With supported fuel and such) running the same amount of boost. I am not saying that their figures were correct, but it makes sense.

So what would happen if you could get the temperature entering the cylinders down to say 50-70deg? Much more condenced air, more fire correct?

 

[rush2252]

This topic has been discussed. The benefits dont outweigh the drawbacks of the powerloss associated with running the A/C you seen an approx 3% load on most motors with the a/c on at idle.


Kolby

 

[waterman412]

yea its a plausible idea, but you would probably gain more horsepower by just taking your a/c out completely, and would lose a small small amount of weight in the mean time

 

[kthackst]

As rush stated earlier it unfortunately can't be done.

There are two rules to Thermodynamics. In laymens terms;
1. You can't break 100% effiency of a thermodynamic cycle.
2. You can't come close to 100%.

So even though you are creating cold air with the a/c, the energy required to make the cold air is greater than what you get out. This is due to the laws of nature and the loss of energy during the A/C cycle. If you think about it taking cold air from hot air isn't natural or easy. It takes four steps to get cold air from hot air and during each stage energy, essentially, is lost.

Four years of engineering classes finally paid off...