High flow coolers on an SR20.

[Ben Fenner]

Peter, I don't think you're seeing what I am talking about here.
Imagine for a second you have two intercoolers. Their cores are the same
exact size. Lets say they are 5" tall, 30" long, and 3" thick.
You can flow the air through this intercooler many ways. The two main
ways would be to pass the air from the 5" side to the other 5" side.
Here is a picture from www.johnnyracer.com of what that would look like:

http://www.johnnyracecar.com/hmt60203g.jpg

The other common way to flow the air through the intercooler is from top
to bottom. From the 30" side to the 30" side. Here is a picture from
www.fwdperformance.com of what that would look like:

http://www.fwdperformance.com/store/Product.asp?IDCatalog=64&ProductID=174

The intercooler can be treated as just another pipe. The thing is, as
pressure goes up, the resistance provided by the intercooler grows
unlike a straight section of pipe. The first intercooler has an
effective pipe diameter, as does the second intercooler. The effective
pipe diameter of the first intercooler is probably close to 2.75". That
means at zero boost, you can flow through it just fine. At 20psi it will
become a brick wall. The effective pipe diameter of the second
intercooler is more like 16.5". This allows you to run much more boost,
with much less back pressure. Keep in mind none of these calculations
are terribly correct. I just couldn't find a decent web page to describe
it, so I've done my best job here, which is pretty poor.

-Ben Fenner
1994 Black SE-R

Peter Serwe wrote:
> I'm *reasonably* certain there's no backpressure
> issues with Tyrus' IC's.  Truthfully, I can't imagine
> how a 12-18" difference in the length of the flow
> direction can actually increase the backpressure
> dramatically.  I can see how non-smooth turns and
> drastic diameter changes affect flow dramatically,
> but I don't get the straight-line shot problem.

> If anything, I would think that pushing the same
> molecules of air over more cooling surface area
> would cool the air more effectively?

> Peter