johnisenglish

Forgive me if this is a repost, but I did several searches and didn't come up with anything.

Anyway, I've been thinking about ways to seriously lower the temperatures of the intake charge in a consistent (at least somewhat street-able) and cost effective way. I started thinking about Air Conditioning systems, which are designed specifically to lower the cabin temperatures below ambient air temperature. They work by compressing refigerent (thus heating it up), cooling it with a condensor (like coolant though a radiator, or air through an intercooler), and expanding it, lowering the temperature even further, now below ambient air temp. The refigerent is then used to cool the air going into the cabin.

SO, why not apply the same principle towards intercooling the air charge? You could even use the stock A/C compressor and condesor, and simply run the refigernt though a heat exchanger similar to an Air/Water Intercooler. Even if you didn't get the charge temperatures quite to or below ambient temperature, it would still be a pretty major drop.

The only two drawbacks I see are parsitic power loss - the inevitable result of using a belt driven compressor - and the fact that high pressure refigerent can cause problems if it leaks. However, the power loss could definitely be made up for in the power gains from lower intake charge temperatures, not to mention the added protection from detonation.

This seems like a really cool idea, and I've been doing to looking into A/C systems to get a better idea of what would be required. However, being that it dosen't exist, I have to wonder if there's some crucial problem that I'm overlooking?

Any thoughts or flames?

Full-Race Javier

FWIW, a well designed air/air IC will lower charge temps to almost ambient temperature.

i believe ford does something similar with their lighting, IIRC they only gained 20% more heat dissipation from this system.....and it wasnt for long periods of time.

johnisenglish

From what I've read (which isn't much, so I may be dead wrong), I thought that the Lighting uses a reserve of chilled water/gas/whatever, and using that to cool the charge temp down only under heavy load

The condensor idea would theoricilly be able to lower the charge temps below ambient temperature, which would definetly out do even a 100% air/air or air/water setup. It would even cool your temps off boost too...

Full-Race Javier

how much do u expect the air charge temp to drop? how much power will be "freed" up? how long will AC cool the IC? basically, u have to figure out how much power u expect to generate and subtract the amount of energy needed to run the system....its all conserved, its hard to get something for nothing.

johnisenglish

The power loss versus the power gain wouldn't be at all that different from a traditional belt driven supercharger - sure there's loss of power from having the turn the compressor wheel, but the positive air pressure makes up for it in the end.

The power loss wouldn't be any greator then with a normal A/C setup, which is only a matter of a few hp at the most. Charge Temps below ambient temp would definetly make up for it in the end.

However, this is ALL speculation, and I'd be very interested to hear someone with a more soild base of knowedgle comment on it

EMod Civic

People have been building a slightly different version of what you're talking about with good success. If you run the numbers, you'll find that a typical A/C system doesn't transfer enough heat to keep up with cooling the intake charge in a 1:1 situation. What has been done and works great is to use an AWIC and mount the evaporator core of your A/C system inside the water storage tank. This way, you use the A/C to cool the water to near freezing, then use the thermal energy stored in the water to cool the intake charge. The mass of water helps balance out the thermal load vs the cooling load.

Another simpler setup is to run the cooling water through your hearer core (instead of the engine coolant). Then all you have to do is turn on your A/C and fan and the cool air cools the water in the heater core and stores cold water for cooling the intake charge. Of course, you won't have heat if you do this, and it's not quite as efficient as the other setup, but it's hella easier.

-Chris

shortyz

emods plan is very effective. 1 problem under heavy load the AC compressor turns off, plus it uses HP. so is the hp your gonna gain my lower intake temps going to overcome what u loose to the AC compressor?

TrueNorthStar

I have been thinking of doing a similar setup using an AWIC and a reservoir tank. Basically the same thing as what emod said but I would restrict the flow of water in the system under normal conditions to lower the temperature of the stored water even more. Then when you go WOT it would remove the restriction and allow the water/glycol to flow at a higher rate while at the same time turning off the compressor.

I would also like to use a radiator between the AWIC and the reservoir on the return side of the system to cool off the water/glycol before it returns to the reservoir.

It might be nice to run 2 refrigerant loops, one to the reservoir and the second inside the car for normal AC use. The only drawback I see is the cost.

keebler65

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shortyz &raquo;</TD></TR><TR><TD CLASS="quote">emods plan is very effective. 1 problem under heavy load the AC compressor turns off, plus it uses HP. so is the hp your gonna gain my lower intake temps going to overcome what u loose to the AC compressor?</TD></TR></TABLE>

correct me if i'm wrong, but doesnt the compressor turn off at high rpm as well? (to protect it)

filthy scarecrow

what about this:
instead of spraying CO2 or N20 on the AAIC, evaporate it through the water tank to cool the water in the AWIC. this could easily drop the water temp below ambient and has no parasitic loss, only the weight of the tank/electronics to run it. us a thermostat to keep the water temp within a specific window.. this could eliminate the extra heat exchanger altogether. only downsides i can think of are
a: refilling the CO2 tank often
b: potential carbonation/aeration of the water in the tank (which would decrease its ability to absorb heat)

maybe use aluminum coils inside the water tank to expand the CO2 to prevent the water from becoming saturated with CO2.. any ideas?