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RE: Homebrew IC's

Sachelle writes:
>The 10 pounds you'll save is worth how much in the 1/4 for you? How many
>of us care about an addition 10 pounds in the face of engine feel?

Some of us are looking at this thread, thinking that reinventing an IC isn't 
worth the time, yours OR this lists.  Scott's point (I tend to agree).  
Doesn't aluminum have better heat exchange properties?

>You neglect the fact that I'm doing this from a project aspect, not
>necessarily what's easiest.

Totally agree, I don't think Scott disagrees either.  His point, there are 
easier ways to skin this cat. Cheaper?  Aluminum radiators internally 
tubulated are expensive.

> My criteria is a bullet proof system with
>higher internal and external flow. 

Than what?  The stock IC?  What mods are you running?  The stock audi IC is 
pretty efficient in design for it's size.  What are you figuring for pressure 
drop and efficiency with this higher IF and EF?  Is copper the best heat 
exchanger for this project, or just the cheapest?  

>As I just emailed Robert Myers about, I
>won't be able to get the external surface area due to finning of the stock
>ic, but I'm trying to create a large tube surface area whereas the stock
>ic has a somewhat low one due to it only being two oval core tubes. I will
>attempt to make up for the surface area deficit with core tube surface
>area increase, better internal and external airflow.

Fins per inch increases efficiency of heat exchanger, what's your target fins 
per inch?  Gettting more flow decreases efficiency of a given IC size.  IME, 
this is a massive undertaking, that should have some solid research behind 
it.  What test methods are you going to use to evaluate your design ideas?  
Is the bench test method going to correspond to an installed test?  There are 
some SAE papers on IC's (audis included) available to you.  I encourage you 
to research them, before you start to solder any copper.

>BTW: you go out and get an ic and modify the end caps yourself while
>trying to get it to fit the tight confines while having proper plumbing.
>Give us your results. I'd be very happy to see them. BTW on that: I've
>tried. Hope you can do better. It's really easy to propose to someone else
>to modify another ic and esp, the tanks. It's another for one to do it

BTDT.  modifying the end caps, if it's out of your area of expertise, can be 
done by a good aluminum fabricator.  If that's not available to you, the 
stock 91 200 IC is.  If your time is worth anything, there are better ways to 
spend your research and dollars.  There are plenty of stock IC applications 
that are available at yards for a song, btdt.   All can be modified.  

>The reason why the thread hasn't died is because it's a point of interest
>to the list. Maybe not to you, but just like a tv station; your option not
>to open the letter asnd delete it. 

You may not think IC design is anything special from a fabrication 
standpoint.  Several of us following this thread, think you may have a huge 
practical application and production problem ahead.  

>I've been receiving many private emails and I try to respond to all of the
>questions and suggestions for the ic idea. The thread appears to be alot
>stronger than you think it is.

For now.  The problem with IC mods is, that they are expensive.  I argue 
that's for a reason.  A copper core IC isn't as efficient as an aluminum one 
for starters.  Internal tubulators increase IC efficiency, but decrease flow. 
 This is way beyond the basics that Corky Bell presented in his book. You can 
buy open end (no caps) aluminum IC cores in a plethora of sizes from Spearco, 
and spend a lot less money on a better IC, than the avenue you are chasing.  
What you will find (btdt) is that finding a space to put a bigger/better IC 
is the toughest part of the equation.  The best B4B mod is the stock core 
with new end caps, cuz you already *own* the core.  To enter into the IC 
design arena beyond stock = bigger, you must modify the existing structure of 
the car, which becomes a huge safety issue (read crossmember modifications 
required in the 5ktq, btdt), that would apply to both the 44chassis and the S 
car chassis, btdt.  

How do some of us know this?  Not redesigning (reinventing the wheel) and 
building an IC, just with using the existing products from Spearco or from a 
stock non marque turbo car.  What exactly are you proposing to make "better" 
out of copper?  Do you know the different reasons for the different designs 
inside and out of IC's?

So pardon a few of us skeptics.  If you really have that much interest, maybe 
you could establish a website.  

>If you're not interested, don't read.
>BTW: I am open to design critcisms and in no way take offense; may help
>the idea come along.

>From one that has plenty of btdt on this concept.  Set some goals, what 
you've propose so far is a pretty crude concept.  Things like:  Efficiency 
target, flow (do you know what the stock turbo flows?), pressure drop, 
recommended/minimum modifications (ecu, exhaust, turbo), size, feed pipe size 
and design to and from, location, front structure mods, attachment points, 
air feed design, heat soak properties.  Plenty more, but don't let me be the 
grinch that stole the copper IC xmas :).

Just a bit of a skeptic on this one...  Happy to be proved wrong.  I'm still 
thinking website though.  

You certainly are on track to learn a lot about IC's though, I say *that's* a 
good thing.

Scott Justusson
Da Grinch
'87 5ktqwRS2 -10vt single pass IC
'84 RS2URQ - 20vt non marque modded single pass IC
'87 4Runner turbo - non marque stock single pass IC