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Re: Homebrew IC's

In a message dated 12/9/99 2:05:17 PM Central Standard Time, 
sbabbar@iris.nyit.edu writes:
>For myself, this is an easy idea.
Ideas are easy, I have no problem with that.  Effective execution of them 
aren't, btdt many times.

> My only roadblock right now is finding
>cost effective core tubing. It will work in assembly terms once I get it.
>Sometimes working from scratch is better than reinventing an already
>established product. My core has damaged lower tubes. You reusing core
>idea is no good. Spearco, tap and, aluminum fabricators are expensive.

A stock core (with damaged end caps) can be had for a song, btdt, I 
reluctantly paid a guy 25bux for one a couple months ago, I really didn't 
even want it.  What is the price you were quoted for the conversion to single 
pass?  Or is that just a statement?  IMO, I'm just seeing a lot of excitement 
here, without a firm grasp of targets and reasoning.  What do you figure your 
pressure drop to be?  What is your targetted efficiency and flow?  I can 
share this with you:  Beating the efficiency and flow of the stock size audi 
IC's isn't easy.  How big is the IC you are putting together?  Are you making 
it single or double pass?  Are you making a plug in replacement for the 
existing IC?  If you are, there are better options available to you.  That 
said you might meet your target of more flow, if that's really what you want. 
 Given your 10dollar boost mod, I'm not convinced that *should* be your 

> In any event, this idea is a simple one for me. I've made more intricated
>  things in the past. As far as the assembly, it's going well and everything
>  is sizing up. If you don't have a good understanding of things, that's
>  fine. This is no skin off your back as far as how hard it is, so it's best
>  not to discourage someone from a project about that. Rather,
>  discouragement should come from a bad design point of view and I don't
>  believe that the list had a detail that was descriptive enough to be able
>  to fully understand. I could comment on the rest of your letter, but you
>  really need to read up on Physics, thermodynamics, and thermochemistry.

Ok, I'm all for projects, btd plenty.  I'm a homework kinda guy, a practical 
engineer, the lab guy.  From what I've seen from you on this subject, you 
*are* trying to reinvent the wheel.  I have no big problem with that.  What 
might help someone who has free access to a university library, would be some 
research.  To start this project, I would look at the objectives I posted to 
you.  But FIRST, why not just do some basic review of the literature to make 
sure what you are doing, is worth the effort.  Why is more flow internally 
and externally your objective?  I can share with you a story about a audi 
vendor that offers a 20vt IC "upgrade" that claims to flow 20% more air than 
the stock.  Guess what the *actual* installed results dictated? 

>Haven't you ever had a creative idea? Ever wanna just follow through?
Many times, including on this very subject.  What I found was, reinventing 
the wheel costs time and money, and usually you find that what has been 
invented on a mass scale (not a one off) usually has better results wrt 
targets.  But here you don't have any really.  Better internal and external 
flow is oversimplifying an IC.  More surface area inside and out of a heat 
exchanger, makes in more efficient, not flow.  So is your primary target flow 
or efficiency?  Why?  What are the design flaws in the audi IC?  Any 
improvements that you can see, looking just at the core construction?

>I like Audis because you need some creative thought to put
>things together. Sure, I can spend $750 on a boost mod, but my $10
>wastegate controller setup works just fine. BTW: I was told that it'll
>never work right and that my engine will always run lean.
A 10 dollar mod, to me, is like a motorcyclist with a 10dollar helmet. Ever 
measure if you are running lean?  You could mod the WG for less than 10bux if 
you want to.

I've done plenty of homework wrt to IC's Sachelle.  Based on it, I'm not 
convinced you are heading in the right direction.  I'm also not at all 
convinced that it takes a huge knowledge of physics to understand how they 
work and what they do.  Simple math is all it takes.  And all that simple 
math gives you is a "guesstimate" as to what it does in a given car.  Until 
you actually get a reading (b4 and after IC) installed you are 'best 

Again, I don't want to be the grinch that stole the IC.  I'm just the realist 
and practical engineer looking at information in the context of other 
information:  mine and the documented.  IMO, you have an oversimplified the 
concept and understanding of IC's.  I predict your end measured results will 
reflect that.  Best of luck to you.

Scott J