But in this case your analogy doesn't fit. It's better to say 1 thin piece or 10 thin pieces, since a larger intercooler is just more of what makes the smaller one, i.e. more fins and channels, and probably not made of thicker metals.

Now which one will draw more thermal energy away from the heat source, the 1 thin bar, or the 10?

 

I have a question that's probably stupid...but m7 claims that at 65 MPH inlet speed, the exit speed is like 200 or so MPH. With the speed increasing in such a short distance isn't it going to create heat with the resistance within the DFIC????? I don't know that's why I ask. -- Johan

 

Not a stupid question at all!

Air doesn't begin to generate heat by friction until close to or beyond supersonic speeds (~760 mph). There is some heat generated by the compression in the scoop, but it appears to be minimal as it's constantly fed with ambient temperature air. Think of it like putting your thumb over the end of a hose. The water that squirts out through the smaller hole that you leave is going much faster than the water traveling through the hose. Same basic principle.

 

Isn't that caused by back pressure?

 

Your right! DUH! When I skydive and freefly at over 200MPH I don't feel my face getting hot. Thanks Will! -- Johan

 

Your face isn't being compressed ether. I hope not anyway.

 

For those who don't have a DFIC or haven't seen one up close; the scoop forces the incoming air thru a smaller venturi then immediately opens up after the venturi. So any air being compressed will release this stored up energy before it (the air) enters the DFIC. I think this would cancel out the effects of any heating that may occurs. Was my thoughts when designing the scoop. Anyone have thoughts on this?
JS

 

I thought Compressed air gets cooler as it gets compressed... not hotter? Why does my air compressor get cold when it fills up with air?

 

You've reversed the argument. I was discussing the time it takes for a larger mass to dissipate heat to X level will be greater than a smaller mass. I also mentioned the perforated material since I knew the bar argument was going to perceived as incorrect.

This time your description is flawed. You talk as though an IC was 10 discreet pieces. It isn't. All the parts on an IC touch. It will act as a single thermal mass.
A larger mass takes longer to cool than a smaller mass all other variables being the same.

I am not and never was talking about a larger ICs capacity to cool the induction charge. All I have ever mentioned was the physical constant that a larger mass will take longer to cool than a smaller mass if all the independent variables are identical.
The inverse is also true but let's stick to just the one side for now

 

You have a magic compressor

Compression always creates heat. Be it solid, liquid or gas.

Back on subject. It gets cooler because the gas escaping the compressor itself into the tank expands.
Test this. Empty your tank. Fire up the compressor and keep your hand on the little finned part by the wheel that goes round and round.
See how long you can leave it on there.


I am not liable for any injuries incurred should you actually do this

 

Ever seen a sky divers face at 200mph?
It's compressed all right

 

The variables are not the same as the way the top feeding intercoolers receive the incoming air is in a much more restrictive manner IE : two 90 degree turns and a VERY limited exit . We see the numbers begin to drop after anything over 15 to 20 MPH with the DFIC. A bad design with a bigger capacity is still a bad design. Maby a interesting question would be if the bigger mass had a design for superior flow would it then cool faster than the smaller mass with a more restrictive flow ? So many questions so little time LOL .

Randy
m7 Tuning

 

That's all true Randy but really the discussion is simpler than that.
A bigger IC takes longer to cool, period.

Drop em both out of an airplane at 30K feet. The big one stays warm longer.

So little time????

I can argue this crap for days

PS: This has nothing to do with the DFIC so let's stop comparing everything to that K?

 

Yikes! That hurt! I'm sueing!

J/k.

Apparently i was thinking of the cold pieces that are left when compressed air leaves a can of compressed air. DE DEH DEEEEE!

 

LOL I've burned...or froze...My hand from that once or twice -- Johan

 

Yes, same thing happens with the DFIC. The pressure builds up in the scoop before the DFIC, and is released as it goes through the fins.

 

Not really. A bigger IC has more matter, but it also has more surface area. Given the same flow conditions, i.e. same volume of cooling air per unit area, they should cool at about the same rate. In the MINI, a bigger IC in place of the stock IC will exhibit a slower cooling than the stock IC, not because it's bigger but because you do not have an equivalent volume flow per unit area, unless you change the scoop along with the IC. Dropping them out of an airplane, though, and they would cool at equivalent rates, assuming similar materials and similar construction.

 

I think I can safely say that 10 thin bars is 10 times the mass as 1 thin bar, and yet it would cool at the same rate because even though there's more, with 10 times the energy, there's also 10 times the surface area. Same siutation in a larger IC.

 

Wrongo.
You're still describing them as 10 discreet pieces. They aren't. An IC is a single thermal mass and will act accordingly.

Materials, fin density, tube design, air velocity, phase of the moon all but one of these will affect how well it cools but none of them changes the fact that a larger mass takes longer to dissipate heat under identical parameters.

 

PS: This has nothing to do with the DFIC so let's stop comparing everything to that K?[/quote]

Then what in the hell is this discussion doing in the DFIC number thread Just kidding ,theorize away

Randy
M7 Tuning

 

Then what in the hell is this discussion doing in the DFIC number thread Just kidding ,theorize away

Randy
M7 Tuning[/QUOTE]

Parallel topic

 

Was a joke, son.

 

To paraphrase, wrongo.

Look at the mathematics of heat transfer, and you will find no mention of the mass of the object. You will find thermal conductivity, temperature of each material (thermal content), transfer barrier thickness and thermal conductivity, and most importantly you will find surface area. Not mass. A larger ic is a single thermal mass with more surface area. If a larger intercooler is made of basically more of the same construction, which is assumed, then it's much more like 1 thin bar vs. 10 thin bars. Your analogy with the large bar and thin bar gives two bodies with vastly different ratios of surface area to thermal energy, which is why it cools slower, not because it has more mass.

Linky:

http://hyperphysics.phy-astr.gsu.edu...mo/heatra.html

 

I can't believe I spent so much money going to college to study (among other things) Heat X-fer

I wish I woulda had NAM back then

 

Very cool link. I even understood some of it.
Let's try this.
We magically suspend 2 500º ICs in the middle of a room with no air moving. One large, one small.
Which will reach room temp the soonest?
How about with a 5 mph breeze?
Which one will store more heat energy?
Which one will have more energy to lose?

On my way to pick up my car from getting an alignment.

See ya in a couple hours