I'm installing mine now... and I hope to have some numbers to add, but nothing as concrete as what we can expect from Matt. And I just spoke with Peter - the 100th DFIC has been sold!

 

I'm glad that you are finally getting yours .... DFIC that is

 

both good and bad.... But I'd suggest that we drop this one of the 1 vs the 10. These problems are pretty much solvable, and thermodynamics has been pretty well buttoned up for quite the while...

So, what's the way I find most insightfull to think about these things (ICs, that is)? In terms of flux.... Heat flux, air flux whatever......

Ignore all the shape differences, hyperspeed gasses and the like. Now, what is the maximum amount of energy that can be taken via a perfect IC? Well, it has to do with only a couple of variables.... The temp, pressure and flow of heated air, and the temp, pressure and flow of cooling air. If the IC is perfect, no matter the shape, then all the gasses will be at the same temp when they go their repective ways..... Since the heat capacity of the two air streams is the same, you will find the final temp is a function of the ratio of the molecular flows.
Why do I write any of this? Because it comes down to the most basic element. Flow the most cooling air you can to get the coolest IATs. Strip all the other stuff off, and these things (DFIC and Alta flow through design) work because the improve the flow of the cooling air.

OK, we don't have perfect ICs... So how does one modify this to get closer to the real world?
1) Pressure drop. Flow through designs have lower pressure drop.
2) Residency time. The DFIC has larger internall volume in the same length, so it has a larger internal cross section, gasses go slower though it than the stocker, so the DFIC has an advantage there as well, the intake air spends more time in the IC to get cooled.
3) Thermal mass and conductivity. This one has to do with the particulars of construction, and the materials used. The stocker is a very light unit, that for sure, but I don't really know here. Anyone have one of each I can cut open with a band saw?

Anyway, I'm still noodling over the thermodynamics of wills models, and I'm still abit confused. Some days I say "Eureka!" and somedays I say "BS! this is perpetual motion". I don't mind not really knowing, I just hate the fact that I change my mind after each long winded post on the issue, and just end up deleteing them!

Matt

 

Dr O - If /when you get the DFIC what measurements will you perform and what other IC's will you compare the DFIC to? Is the bottom line which IC has the best combination of thermal efficiency and pressure drop? If you get good DFIC numbers, which I suspect will be the case, another 100 DFICs will probably be purchased by the "need-the-data group" that are patiently waiting. Is the DFIC in the mail M7?

 

Don't equate mass with surfase. The mass is there ( larger IC ), yes, but it's spread out over a larger area. You have a radiator to cool the engine, would a small radiator cool better than a big one, given the materials, fin density, tube design, air velocity? And the thermostat for the IC is the TB.

Take 2 ice cubes 1 twice the size of the other. Break them up so the surface of the fragments is about the same size. If the ice is placed in the same enviroment both cubes, equaly spread out, will melt at the same rate.
This is a very over simplified method of explination. Bottom line you melt twice the mass at the same rate. The same is true when you re-freeze it.

What makes the M7 solution work is the surface arrangement. The mass is there, no argument, but so is the surface.

 

Yoou're also not getting what I'm saying. That is very possibly my fault.
I neber once questioned that a larger surface area will transfer more heat during a given time period.
What I am saying is that a larger IC has more mass. It'll hold more heat.

Heat large and small to identical temps. Saturated to the core.
Suspend them in a room with little teeny low conduction threads.

Are you saying that the larger unit will reach ambient before the smaller unit? At the same time even?
Under these conditions the internal and external temps will be identical in the ICs so we can dismiss the thermal conduction of hot internal gasses everyone keeps bringing up.

Given that I am saying materials, construction, and therefore conductivity are identical then the only variable is thermal mass. A variable I was told earlier wasn't important. Now that THE Dr has said mass is part of the equation is it more believable?

I'm kidding Matt. We all respect what you bring to the table. I just find humor in the instances where someone says something and it's all stupid then you say the same thing and it's all "OOoooo did you hear what Matt said!!" And of course the "stupid guy" never gets an apology.

 

I'll be getting a hand off at Monterrey.... We'll see if demand forces any more delays....

As for what I test, it comes down to a couple of things...

1) Pressure drop vs RPM in neutral. I have data from: stock, Alta TMIC, Alta Prototype, GTT. This gives a relative comparison of conductivity.

2) 2nd gear red-line thermal efficiency.

3) Mass of fuel delivered (what the ECU sees for how much to squirt)

4) Timing retard

5) I also get G-Tech HP deltas, but they shouldn't be taken as an absolute, more like a relative or % change.

6) a freebee is 40-60 MPH times, some real world "Area under the curve" data.

I use a g-tech so I get real word airflow. My car is a bit of a different state than last time, so the absolute numbers may not line up. But I'll test the DFIC against stock so one can get an idea of what the product offers.

Matt

 

I too am interested in this mod. With 100 sold wouldnt there be some who could comment on their 0-60 or 1/4 mile times. Soooo much theory, real world times are a true comparison and improvement of a particular mod to a particular car. Will the DFIC be a mod that will reduce my 0-60 time under only certain situations , like hard running for extended periods or very hot days? Or can i count on it to provide more power in the best of conditions assuming all things equal? Jim

 

Obe, "And of course the "stupid guy" never gets an apology. ", no, what you are saying is partly correct, there is some thermal cooling loss with the added mass but it's minimal. Use the ice comparison, you have the same material, mass x & mass y ( y = 2 x ), then expand the surface to optimize melt, if the surface of both x & y are equal they will melt at the same rate. This applies to the IC as well. Air pressure and what ever elese you want to throw at it, won't make any difference. The DFIC has the best optimized design for the job ( IMO ).

Sobendmini, IMHO you would see the benifit of a lagger IC or the DFIC at higher 3500 and it would be quite dramatic under all conditions. I have neither so someone else would be more able to answer your questions. And welcome to NAM......

 

here's the key.... Use polysillabic vocabulary that give cheerleaders headaches, and become Dr Obehave! Then no one will ever question your pearls of wisdom!

Matt

 

Indubitably. The veracity of your astute observation bears consideration in concert with a subtle stratagem of implementation.


Pearls and the occasional Rocky Mountain oyster are dispensed similarly

 

I feel a desire to bask in the glow of your obvious wisdom! I bow in you're general direction!

Matt

 

So what really needs to be stated is the mass to surface area ratio between the 2 ICs.

But...... You cannot optimize the surface area of one and not the other.

Glad you said that though. It helps. So really, without knowing the relationship between increased mass and increased surface area we/I don't know.
Core depth and fin density have a dramatic affect on efficiency.
Wonder if I could borrow a fin count tool from where I used to work. That'd be the most tedious part. Hmmm...

 

that this particular thread of armchair science isn't really bearing any fruit...... But to count fins, just do 2-3 inches, that will be good enough. Then you can just measure the length of the finned area.

Matt

 

I'll take my small fruit thank you very much
Yes we used to use 2cm and exrapolate from there. Still a PITA when a fin count tool does it in about 3 seconds.

Still fun to discuss while we're waitng for real numbers from some guy............................................... .................................................. .................................................. .................................................. .................................................. .................................................. ...........................Oh!! That's right....it's you we're waiting on:impatient


Back to my comfy armchair.

 

Seeing as he doesn't make any money of sending my mine, I can see why I'm at the end of the list. And Tony is starting to userp my quantitative role! I"m feeling all kinds of inadiquate....

And with your newfound polysyllabic tendancies, I may quickly become obsolete!

Boo hoo....

Matt

 

Understood.
Tony deserves a bit of sunshine though.

 

Well, now that I've walked away for a day, I have the perfect example of what I was trying to say, "Will's model" apparently. Take two 1 KG pieces of metal. Both are heated to the same temperature throughout. One is a solid cube, and the other is flattened out into a really thin sheet, like aluminum foil. Both are suspended in air, and let to cool. Which one reaches ambient first? Keep in mind, they are the same mass.

 

I love science...

 

Undoubtedly the thinner but we are not talking about 2 objects of the same mass. If you thinned out a 2 lb block to .050" and a 1.75 block to .050" which will reach ambient sooner? Thats what we're talking about.

Note: From memory the aftermarket unit are 10-20% larger. My GRS for instance has a ~ 13% larger area on the top surface over stock. Measuring fin area only. ~18.4% greater cu/i

Stock = 10.875 x 6.375 x 1.875 102.5 sq/in and 205.3 ci/in

GRS= 11.250 x 9.125 x 2 89.33 sq/in and 167.5 cu/in

I think stevecars60 mass to surface area ratio comment makes the most sense.
Taking that into consideration there might not be as great a time differential as I first thought but there still would be one.

If the mass goes up 20% but the surface area only goes up 15% then there is a loss. Made up figures but they demonstrate my intention.
Bear in mind that a large portion of the mass increase will be in the end tanks,including the tube ends, which assist very little in cooling the charge or the entire unit for that matter.

Back to my comfy chair

 

Boy--I wish I could follow this thread! But, unlike some of you, I have a DFIC in my hands, just obtained at MitM about 2 hours ago. I don't have my calipers with me, but the one thing that really interests me is the density of the fins on the inside of the IC--they are arranged very differently than the fins on the outside. The external ones that the cooling air passes through are simple fins like on a radiator, and I can see through to the light on the other side quite easily. Not so for the internal fins. I can hardly see any light passing through. I wonder if this complexity and density might contribute to greater pressure in the IC and longer time spent in the IC to get more cooling effect--as per Dr O's remarks?
Anyway, mine's number 023 (engraved on the top of the DFIC).
cheers,

 

The value of note posted so far is TonyB saying his boost gauge read the same. Although not definitive it is a nice indicator that the DFIC core flows similar to his GRS which had a very mild pressure drop over the stock unit.

Randy had posted in his testing that the GRS had a .5 psi drop comapred to the stock unit.

 

Yes, if I read Dr O's post and understood (some) of it, the DFIC has a greater volume which is good since the air gets exposed to more cooling while travelling through it, but if the pressure drop is not great, or negligible, then m7 did a good job of keeping the air busy while travelling through the IC, so although lingering, it didn't lose any of it's oomph.
Gee, I'm not a physicist, am I? A social scientist, yes. 8-)

cheers,
PS--does anyone know of a thermocouple or probe that will fit in the bungs on the DFIC? thanks, I want to start taking measurements.

 

Let's see...Peter, Randy or Sid could tell you.

I'm not a physicist either. I just like to aggravate one

 

cheers,
PS--does anyone know of a thermocouple or probe that will fit in the bungs on the DFIC? thanks, I want to start taking measurements.[/quote]

As mentioned one the web site for you number's guys

Included on the intercooler are two 1/8th inch NPT threaded bungs which will allow thermal couple placement for pressure testing instruments or boost gauges pre-core and post-core.


Randy
M7 Tuning