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Member Thingy
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1,120 Posts
Discussion Starter #1
I was going to reply to another thread with this, but I figure it's something some other people might want to see as well. I'm finished with this project, but these pics are a bit dated and I don't feel like tearing the car apart to illustrate how everything is laid out, so i'm going to draw a few things in. I'll get around to producing picutres of the final result and performance data after I get some "after" numbers.

The car I built was originally designed for roadcourse use. The problem is installing a shiny new FMIC to cool the intake charge also restricts airflow to the radiator. There are numerous solutions to this dilemma, but I decided to do something a bit more aggressive.



I decided upon a vertical mount intercooler, which, for a number or reasons, is in and of itself a benefit to performance, providing less pressure drop across the core, less weight, less restriciton to flow, etc. But that's another thread entirely. With a vertical mount setup, the endtanks for the intercooler are on the top and bottom, rather than on the sides. This frees up valuable space which can pass air straight back to the radiator, and frees up space in the passenger air duct, where the SMIC used to sit which I now house my intake in:



Now that I'm guaranteed a fresh charge of cold ambient air from the intake which sits in the former SMIC duct all by itself, the trick it to get enough air through the intercooler to keep that charge cool. So here i'm about to install ducting to keep airflow smooth going through the intercooler, and at a decent velocity. That piece of paper is now aluminum - I figured there would be a good chance it might rain at some point and my crafty intercooler duct would turn to mush, so I might as well make a proper duct while I have the car apart.




As you can see i've left lots of room behind the intercooler and between the radiator so that there is pleny of room for air to collect and then push through the radiator. Also, this allows me room to build a large intake duct below the radiator, much like andi b's car, but more on that later.




Oh, before anyone asks how I got the intercooler pipe out from the top of the intercooler to the throttle body without bisecting the airspace which the radiator sucks air from, here's a good idea of what I did.



The intercooler piping exits the top tank of the intercooler on the drivers side and shoots striaght back - right through the radiator, err, where the radiator normally is. Now you might ask why I would cut 2" out of the drivers side of the radiator when my goal is cooler engine temps. I have not tested this yet, but calculation and theory says that I lose very little cooling by reducing the number of vertical rows the radiator has, but rather, I lose flow. To compensate for this, I had a custom radiator built which is slightly narrower than the stocker, but much deeper, ala PWR. This bad boy can outflow the stock radiator by a huge margin, and should compensate for my lost coolant capacity easily. The stock radiator in the pics is functional, but a test-mule installed for measurement only.

Here you can see the intercooler piping exiting the intercooler endtank and going straight back.



Finally, under the nose of the car I built a diffuser which sucks air from under the stock lip, and draws it up and into a little duct which shoots it directly to the radiator. This picture was right before I installed that stuff; it gives a good idea of how it all sits underneath the intercooler and radiator. It's only a half inch lower than the stock plastic panel which sits there, but it's metal and rigid, so scraping curbs is out of the question.



Hopefully in a week or two I will have some coolant numbers which might indicate better cooling. However, I also swapped the turbo down from a 67 to a 61, so there might be a little bit of error. But hopefully temp at idle and a few other points of interest will give me a good place to start to make a judgement.
 

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Member Thingy
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1,120 Posts
Discussion Starter #2
I want to mention also, given the choice again, I would opt for a sidemount setup, probably twin sidemount intercoolers, one on each side, and an unobstructed radiator inlet. Virtually nothing beats that setup for cooling capacity.
 

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On 2 wheels
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750 Posts
Whoa, awesome explanation man.

Upgraded side mounts would definitely have been less of a head ache but where's the fun in that right?
 

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Member Thingy
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1,120 Posts
Discussion Starter #5
I was just thinking about your idea for having intake air from under the car for cooling radiator. Rather than forcing air through the intercooler and then thru the radiator, wouldn't such a large undercarriage opening allow air that we would like go thru the radiator pushed down under the car instead. I know there is a ramp like piece that you've incorporated so therefore the air would be drawn up, but I just think maybe you could extend the ramp a little further forward so air being drawn in and up is the only place air may travel. This is from looking at your last pick.
This is something which I theorized would be a problem, but had no way to test it without building the setup first. As soon as I get the car out on the road i'm going to place a tiny wireless camera in the area, with a wire mesh which has a series of tells (little plastic strips of garbage bag) on it, and watch how they move at different speeds. Hopefully up to 150 mph they will always be sucked inward, toward the radiator. If at any time, i begin to lose air from the area, I will insert a duct which separates air intake from below, and air intake from the front of the car, giving the air intake fro below the bottom 1/4 of the radiator to pass air through. This should solve the problem, and give smoother airflow through the radiator.
 

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Premium Member
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10,170 Posts
Jaxx said:
Upgraded side mounts would definitely have been less of a head ache but where's the fun in that right?
I don't know about you, but my life is crazy enough that I don't need to create additional headaches for myself. lol. That's just one reason the sidemount is a good choice.

Chris's solution should be great as well -- just requires more time and $$.
 

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Super Moderator
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10,498 Posts
VERY NICE work, Kale. I look forward to your testing. May I ask where you had the custom radiator fabricated?

Ken.
 

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1st Lieutenant Team BEYAW
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1,915 Posts
good to see your ideas coming to life, Chris. Hopefully i can see it soon in person. good luck on the numbers!!
 

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770 Posts
Great post kale, having wondered before how well similar mods would work, I can't wait to see how they turn out. I don't road race it, but those little things interest me, top work.

Will the plastic tells show you enough? or could you be better off mounting a tiny wind speed indicator - you can get small cheapo windspeed measuring devices from nature/outdoorsy stores (I'm thinking Australian geographic here, don't know the equivalent over there). The plastic might still be flapping lots, but not _really_ show you the airspeed - especially since those wireless cams can give pretty poor picture quality on fast moving objects - could be interesting video though :)
 

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Member Thingy
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1,120 Posts
Discussion Starter #11
May I ask where you had the custom radiator fabricated?
I had the radiator built by an aluminum specialist local to me, the same guy who made my intercooler brackets. The radiator is actually still not in the car, I have to go pick it up sometime soon when the brackets are finished, the welder I am using doesn't have much time, but I have to say, his work is worth the wait - he agreed to work on my intercooler and radiator in his spare time inbetween his projects for NASA and his experimental telanium? submersible.

Will the plastic tells show you enough? or could you be better off mounting a tiny wind speed indicator - you can get small cheapo windspeed measuring devices from nature/outdoorsy stores (I'm thinking Australian geographic here, don't know the equivalent over there). The plastic might still be flapping lots, but not _really_ show you the airspeed - especially since those wireless cams can give pretty poor picture quality on fast moving objects - could be interesting video though
great suggestion; that's just what I was looking for. That would give me direction AND numerical data. The best I had come up with was a small pipe with a maf sensor in it, and had ruled that out.
 

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The new #1 Hardtopper
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1,572 Posts
Nice work Chris, cant wait to see the finished product. I know you have been brainstorming this for quite sometime now. In reference to the airflow, I have wondered ever since Andi B put that "scoop" you mentioned below the radiator/IC pulling air up in front of the radiator. Sometimes I wonder if the pressure gained from the scoop increases cooling more than the laminar flow that already exists (what little it is). Basically you are introducing turbulance into that area and "confused" air sometimes doesnt cool as well, your thoughts.

Lets see the updated pics, I would like to see some shots of the scoop.
 

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Member Thingy
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1,120 Posts
Discussion Starter #13
brian- this is my logic behind my ducting, crude on paper, but sound in theory, at least to me.

minimal ducting with intake for radiator on bottom of car:



proper ducting with intake for radiator on bottom of car, and inbetween radiator and intercooler:

 

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Registered
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6,785 Posts
Nice writeup kale. I also went with a top/bottom FMIC and love it. I gained 3psi and 300 less lag compared to the stock smic(i did a leak test first to assure i didnt fix a broken coupling/pipe so i would have an error proof comparison)
Great job btw.
 

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Supra + DSM = heaven
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Kale! Nice work. I can scan a lot of diagrams for you about drag coefficients and effectiveness of different designs for ducting and the diffuser. Few suggestions sorry late at night work early typing fast

Consider the use of side fins for the radiator venturi as they drastically increase efficiency.
Consider the escape for this air, I dont know how fast you will be going but ducting into the engine bay can result in serious issues with pressure buildup Cheap solution is to raise the rear hood exit and remove the rear hood seal this will benefit downforce, engine cooling and drag as it fills the low pressure area after the initial impact at the front of the car.

I scanned a couple diagrams for you but I cant log into my photo site for some reason right now to host them up. I have some substantial textbook material on automotive aerodynamics. Have you been to mulsannes corner yet?

Given I dont think any of this stuff will be a big concern and I think this ducting will be of huge benefit but if your looking for that last degree of effectiveness here I can get you a bunch of data to help out.
 

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Member Thingy
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1,120 Posts
Discussion Starter #18
Nice writeup kale. I also went with a top/bottom FMIC and love it. I gained 3psi and 300 less lag compared to the stock smic(i did a leak test first to assure i didnt fix a broken coupling/pipe so i would have an error proof comparison)
this is about the gain i'm looking for as well. The area of the tubes vs. their length and depth is theoretically so much more efficient than the standard 3-row. The only drawback, of course, is the higher probability of heatsoak and reduced resistance to it simply due to less mass to absorb and radiate that heat. Nevertheless, overall cooling efficiency should still be better than that of the 3-row I had last. I guess we'll see!

gixxer- I've read what i'd consider to be just an intro book to "aerodynamics 101." I've only found a few really good articles wioth data I have been able to verify and trust, and would love to see some of the material you have.
 

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Supra + DSM = heaven
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Kale, check out mulsannes corner for some awesome free info
http://www.mulsannescorner.com/

thats where I got all my 101 stuff

heres a couple scans i hoped might be helpful

this one for the diffuser design


these for designing your ducting


the toyota GT ONE case study in particular might be useful
http://www.mulsannescorner.com/gtone.html


they did something similar


I modeled a lot of my aero work after the GT ONE (whatever class regulations allowed me to get away with and a mere mortal could afford)
 

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Supra + DSM = heaven
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3,946 Posts
slither said:
Nice writeup kale. I also went with a top/bottom FMIC and love it. I gained 3psi and 300 less lag compared to the stock smic(i did a leak test first to assure i didnt fix a broken coupling/pipe so i would have an error proof comparison)
Great job btw.
that is really impressive, what was the cooling like? How are your intake temps?
 
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