Loginology

I'm not seing a benefit in having a dual stage intercooler. I'm pretty familiar with how an IC works...and it's just not clicking. This is in response to rkives FMIC http://www.cardomain.com/id/rk90gtx


it seems to me that addiding a tank between the two tanks would only make the system more restrictive.

snart

I thought he just had 2 core put together?? I am also familiar with the way an int. works, but how does a "dual stage" work?? Just from the looks of it I dont see any benefit over one big core either.

rkives

Since the intercooler is simply a heat sink, the more area you have to exposed to the heated air the better. The "center tank" is simply a way to join the cores together. The center tank adds less restriction than an end tanks since it simply an open box, not collected into a 2 1/2" opening like the end tanks.

The main idea regarding a "dual stage" is that the pressurized heated air hits one side of the intercooler first. Wouldn't it make sense to use a core with efficient heat dissipation characteristics at that end of the intercooler? The problem with good heat dissipation is that it often comes at the cost of flow. So if the second "stage" had better flow characteristics, you have an intercooler that dissipates heat well where it is needed, but still has a reasonable flow. Additionally, the hot air that does not come into contact with the intercooler surfaces do not get cooled very well, the "center tank" allows the air to mix prior to going down the second "stage" of the intercooler.

The Dual stage intercooler was not "planned" it just happened. You do the best with what you've got. In thinking about the thermal dynamics afterwards it seems to make sense to me and I am very happy with the results. Im not trying to say that its the way you should do it. It just what works for me.

Really, on the street it doesn't matter all that much anyways, your in boost maybe 10 seconds at a time in the city. A little bit more when climbing around the mountains, the intercooler you pick just has to be able to dissipate heat between boost sessions! If your full on racing, that's a different story. I built mine for "daily driving" not for competition or show.

Loginology

The "thought process" behind it makes sense, but if you were to take the same space, and have a top-to-bottom IC with the same surface area, it would most likely have higher efficiency than your side-to-side dual-stage-IC since it would have a greater number of thinner, shorter, channels. Remember that air is NOT going to flow through the second stage any faster than it would have the first stage.

rkives

Of course, you could always be more "efficient" but at what cost? $1500? no thanks. I'm happy with mine.
These are 2 $60 cores joined together. I doubt that a $500 intercooler will be twice as efficient for my purposes, as I said if I was racing it might be a priority, its designed around daily driver.
Keep that in perspective. Besides in Canada cold air is a commodity .
As far as flow, think of blowing up a balloon through a foot long thin straw, then cut it in half an blow it up, it will be easier, because the length adds resistance.

besides, its twice as good as what was originally going to be on the car:




Additionally, you have to think about where the intercooler is mounted and the amount and location of where the cooling air is coming from. A top to bottom IC would be most efficient if the full length of the IC is exposed where hot air is going to be dissipated, that means a custom bumper arrangement. Not to mention that the bottom end tank would probably be in possibly the best location for air pressure, wouldn't cooling fins in that location be more "efficient"? The fact that the pressurized air in a top to bottom arrangement has to take not 1, but 2 90 Degree turns to get to the other side can't help the flow rate!

In my arrangement, the IC is mostly covered by design, but the air flow runs directly over the cooling fins that first recieve the heated air on the first "stage". The center tank recieves no direct air flow but it does add to the structure of the hood latch. On the other side, the cooling air is flowing just prior to where the pressurized air is collected on the "second stage." Finally, the pressurized air has more time within the tubes to allow for heat transfer to occur.

From the stories I've read on Autospeed's site about intercooler efficency, there really isn't that big of a "bang for buck" performance gains with the more expensive intercoolers. I'd much rather spend it on handling upgrades.

Loginology

First let me start by saying I wasn't saying yous hould have spent more on your system... I understand that. As a daily driver only it doesn't matter so much


you can get vertical fin IC's with openins on each side.



Unless you cutt your bumper, air flow has no meaning in your system. In order to be a significant factor in cooling properties, the airflow duct must be atleast 1/4 the core size.

going to your straw analogy..try the same thing with a 1/4" straw and and 1/2" straw with a 1" straw between them. now try to push the ballong through with your lungs :-)

rkives

Even with opening on each side, the air would still have to take 2 90 degree turns with the vertical finned arrangement.
Here's a pair of the my intercooler cores in the configuration you describe:


As far as cutting the bumper to get 1/4 of the core exposed to get benefit: of the 126 square inches of frontal intercooler surface area, there is 54 square inches of direct air flow with my "stock looking" ducted bumper. Thats closer to 1/2 of the core size and the air is directed exactly where the heat dissipation is most needed. With the vertical fin configuration, there will be far more stagnant areas(end tanks) you will be cooling without full benefit, not to mention the additional vertical space requirement. Have you measured the usable front space? You really can't tell by the pictures, it is a "sleeper" after all. Having a intercooler hanging out front really takes away from the stock look that I am going for. Your aims are obviously different. I had the option to go vertical when I was building the intercooler, The dual stage configuration simply makes more sense in my application. Choose your own road.

Loginology

The pic doesn't work. So that opening is a little bigger than it looks, makes sense. I see where you're going with it. I still say the vertical fins would be less restrictive, but at least we're on the same page npw

rkives

I have to use the stock air box to avoid hitting boost cut without a boost controller, I really don't think "restriction" is a problem in my configuration.