The problem with the DIIS concept is that the majority of the intake air does not get to exchange any heat with the dry ice due to the laminar flow characteristics withing the piping. This is physics and all pipes obey it, whether they are blood vessels in your body or intercooler piping. The piping itself may be dozens of degrees below 0 celcius, but only the air closest to the piping gets chilled.

Science Project:
Imagine slicing through the pipe and look at it in cross section. Then imagine hundreds of concentric rings within the pipe. The largest ring touches the pipe and gets cold. The one inside it is less cold, and so on. Air is a horrible conductor, so within a few milimeters of the pipe you have no real heat exchange. To exchange heat, you need surface area. Just like a radiator's fins, or...an intercooler. Load that pipe with fins and it has a better chance of cooling the air, but it will also block air flow. Better off using an air to liquid intercooler and use the dry ice to superchill the coolant.

Doc

 

Has anyone ever seen that old infomercial about some type of vortex circular piece you would put inside the pipe of your intake system? I guess the theory behind this unit is that it would make the air flow better..

 

^ you're talking about the Tornado

It makes air spin around, like a tornado (or toilet flush) going through the pipe. I thought about this. possibly fabricate some type of fan to circulate the air all the way through the pipe?

 

It's more a function of surface area and contact time than the fact that there is laminar flow. Heat exchangers (like intercoolers and radiators) have lots of surface area and retain the fluid that they are cooling for a relatively long period of time so the cooling can take place.

Wargasm is right. This was my first thought when I read about this product, but he beat me to it. There is no way this thing would have a significant effect on intake temps. A dry ice / liquid bath would be more effective, but would probably still have a negligible effect due to very little surface area.

FWIW, a water / dry ice bath wouldn't work because the water would just freeze, and then you'd have a solid block of ice which would be almost as effective as an ice water bath. I use dry ice / acetone baths in the lab all the time and they work well, but I sure wouldn't want a bath of acetone under the hood of my car. Ethylene glycol would probably be a good choice.

 

I found a website sellin the prodcut i was typing about... Anyone have any input about this?
http://auto.272.com/272/products.php...6983486dcc7b1b

 

gimic

 

Excellent point that contact time is also necessary for exchange to occur. And the more surface area, the more efficient the exchange. Laminar flow is a phenomena that occurs in an unbstructed pipe. Increasing surface area and increasing contact time lessens the phenomena.

So I'll revise the statement:
The inherent problem with the DIIS system is that it has suboptimal surface area and contact time for efficient heat exchange.

 

Let me sum it up.

It is a bad idea, and it sucks.

 

Ethylene glycol, I think thats a great idea.. Do you know what the freezing point is??

If you use Ethylene glycol in liq. IC, you might not need the radiator.. just reserve tank filled with dry ice and Ethylene glycol. Hmm..

Maybe use one of these on the IC piping..


I thought about this about a year ago, when I saw this liq/air IC.. I had few debates about using combination of this than just air IC.. now i think set up where ethylene glycol and dry ice will work well after the air IC.. first cool the air than cool it even further with the air/liq ic.. could this work?? I guess real world test is in order..

 

Inside pic of the air/liq IC..



Looks pretty restrictive.. Hmm..

 

I think it would work in concept, but there's no room for it in an FD. If your objective is cooling the air intake charge on a street car, the best setup I've seen is a nitrous spraybar on the exterior of an air/air intercooler. Simple, lightweight, space efficient (one you figure out where to put the bottle), adjustable and cheap. You can use a WOT switch or setup a boost switch. The bottle should last a while too...certainly all day at an event.

 

The melting point of ethylene glycol is -13 C. IIRC, water / EG mixes freeze much lower than that.

 

So how would this setup compare to an intercooler spray bar?

 

https://www.rx7club.com/showthread.p...hlight=dry+ice

I know the link doesn't work any more but this is what others had to say about a year ago.

haha, I just looked at the first post of this thread and it was started before my thread. This must have been brought back from the dead. Plus I can't find 01 Design System web page.

 

It's still there: http://www.01designsystem.com/home.html


FWIW, they list an application for RX-7s as "under development":

http://www.01designsystem.com/diis_pricing.html





.

 

Thanks