im just sitting here thinking about the different ways people have cooled air:
methanol, a2a intercoolers, a2w intercoolers, some sort of cross between a2a and a2w, a/c run intercoolers, a/c/a2w intercoolers, etc.

would there be a way to flow enough compressed air over a relatively small area to equal an intercooler of lets say.. twice its size? possibly a mixture of the 2 (appropriate cowling,etc). of course, the system would have to use a small compressor as well.. no shop tricks. but really, this is all a thought experiment and kinda wanted to see what would show up.

 

i think at that point your just better off with a chemical cryo kit or just icing a air to water... the power to run such a compressor and the amount of air required would be counter productive IMO.

 

plus i have no idea where the thermal efficiency of air would be reached but i imagine after a certain point there are no gains as to how fast or how much air flows past the intercooler as the aluminum will only transfer so much heat anyways? i dunno 10 beers in so maybe im wrong

 

Any time you compress air it gets warm. You need to have cool air passing over it. Honestly not worth the effort.

 

And the opposite when it vents or is released from compressed state to atmospheric pressure which is what the OP is referring to. I don't think it would be very practical though.

 

thats why i asked about feasibility. i would think the best bet would be a cowl of sorts for a smaller traditional fmic and then integrate a spray bar into that about an inch from the fins.

 

You can't get something from nothing.

Either you have to carry so much pre-compressed air on board that the weight kills you or the power to drive the compressor kills you.

 

When did air weigh something? lol..... I know you mean the tank, but its still sounds funny the way you worded it.

 

Compressed air doesn't get cold when its released from a compressed state. Its just the air moving like the wind blowing or a fan. Its not changing any state like from a liquid to a gas, etc. If you theory was true then a turbo compressing air would then be cool air right before it enters the engine. False!!!

 

You could use a smaller intercooler and CO2 set to spray on a hobs switch.

There is a company that is connecting the cars A/C to an A/W setup for the Corvettes. Sounds like what you are talking about.

http://forums.corvetteforum.com/c6-f...-made-now.html

Ryan

 

liquid nitrogen, lol

 

Are you sure? I thought I read some where when I was a kid that when the molecules in a gas are allowed to expand after being compressed they have a cooling effect. Like a refrigeration system.

 

Yes. Expanding gases have a cooling effect. The act of compressing a gas has a heating effect. I learned this soon after getting a nitrous refill...the bottle was too hot to touch. As the nitrous oxide molecules were forced into the bottle, they got closer to one another, and the forces trying to keep them away from one another increased, which in turn increased the internal energy. The increased internal energy increased the heat. The compressed air from your forced induction example, Cam72aro, was never released... it was still compressed, otherwise what's the point of using FI? In instances where FI is released, it's because you had a leak or your BOV just activated... in which case the gases would have been relatively cool. (maybe not cool enough for your fingers, but cooler than when it was compressed). So after I let my nitrous bottle cool (losing all that heat energy) and I opened the valve, the expanding nitrous had to "replace" that energy. It stole it from the things around it... bottle valve, nitrous line, solenoid, nozzle, all the little fittings, and also the incoming air stream. Hence, the cooling effect. The gas itself got warmer, so to speak, and the **** around it got colder.

Hopefully I didn't botch my wording or all hell will break loose.

 

Lots of ways to get low intake temps.

Conventional A2A ans A2W disipate the energy to the outside environment with heat exchangers.

Iced A2W system just absorb the heat and use the phase change of the water 9form Ice) to absorb large amounts. Also you have a very low starting temp.

Dry Ice system (see below link) are very similar to iced water opnly MUCH more effectvie! http://www.are.com.au/Big%20HP/Dry%2...%20cooling.htm

Chemical (meth injection) cooling basically uses a mix of state change and absorbtion to reduce the intake temps. These are very usefull when used in conjunction with either a conventional A2A or A2W system. Dont forget you can only inject so much before the air stream will no longer be able to carry the vapour. this will also impact the AFR of any setup in use. Fuel can also be used (see carb setups).

Spraying an A2A intercooler with N2O or CO2 is pretty pointless in my eyes! you will only see a reduction whilst spraying, it wont last long, and you may as well spray N2O direct in to the intake as you then get 1) the cooling effect and ") the added o2 in the cylinders!

You can actually use a presure reduction in the intake tract to redcue temps. This is what the WRC cars did. They overboosted the turbo (higher than manifold presures), ran a normal intercooler, and than a suden tranition to a much wider pipe. Thios cause a presure drop and enabled them to get sub ambient temps with NO chemical injection.

if using a A2W system you could look into AC recovery systems. These use the engines power to drive a heat pump to reduce temps of the water. Work ok for drag racing where you have time to cool the system but im yet to see a system work for road racing.

The most simple way to redcue intake temps is to reduce the presure in the intake manifold! sounds daft but if you design the engine to work more efficently then you will require less boost to make the same amount of power! Better heads, intake, exhaust, correct turbo sizing, etc, will all result in a more effctive engine that needs less boost to make the same power!

 

yes, temp drops with pressure drop.

chunnington, ive seen those dry ice systems, theyre neat. to go with your over boosting comment.. couldnt you do similar with an intercooler? ie: run a wastegate on the cold side like phil has with his turbo mustang but run that waste gates dump to a spray bar?

you wouldnt need a tank for the compressed air but you would need a good enough compressor to move the air needed at a decent enough pressure.

 

After doing some research I did find out that decompressing air does cool. Its only slightly though. The above example with nitrous is not even in the same ballpark because compressed nitrous oxide is a liquid that turns into a gas and when it reaches atmosphere is cools to around -40 degrees F. Compressed air is not a liquid its air and stays as air any way you slice it. So yes it does cool when decompressed, but the benefits of it would not be worth it. Put a methanol kit on it. Way better results for way cheaper. Keep it simple stupid, don't over think it.

 

We use it(compressed air) to cool cabinets/motors at work in a pinch. When combined with a vortex cooler attachment you can actually get frost to develop on the end. Still this would take more compressed air than one could carry or produce on a car.
The nitrous was used to help explain the theory to you. Nobody said air turns to liquid.

 

I just meant nitrous is different than compressed air. The temperature change occurs because of the change from a liquid to a gas.

 

Why not run nitrous in two fashions. Set the purge valve over the heat exchanger/intercooler, then spray the motor down the track?

 

It always has...

Have you ever carried a full air compressor versus and empty one?

and this