When most of us buy our first exhaust systems we think about the size of the tip, what other people are buying, the angle of the rear section.
We focus on brand names, and pipe size. We here today however are going to go a little deeper into the exhaust system, starting from the combustion
chamber to the muffler tip. The basic idea of the exhaust system is simple to exhaust air out of the chamber.

We have two phases to learn and understand well. When we understand this we change how we look at a particle setup,
or how we can further modify our own to suit the engines needs. The first phase is when exhaust gasses are removed
from the cylinder. After the spark, the exhaust valves open and the compressed gas hits the header primary's in its given
firing order. Then at a much more explosive manner we have a wave of pressure are the port throat.
This happens when the port itself opens. Kinda like when you open the door on a submarine... interesting things happen.

This part, the pressure wave is one of the most neglected. Its very complicated and i don't understand much of it myself..
but basically this is the phase when we want to scavenge, collect, take all that gas out of the cylinder. We do this so that
we can fill the cylinder back up with clean, fresh, ready to be destroyed air mixed with yummy 91 or 93 octane fuel.

This second part, if you want to get super nerdy you can look into "wave tuning" Now this pressure wave is directed
by the size of the header primary, that first section of tubing on a header. From that point the gases move to the midpoint
of the header, the collector. Depending on your setup, tri-y(popular since the 60's) or a 4-2-1 setup, the nozzle area
has to be larger than the primary area but smaller than the final collector size. From that point on the chaos has been
decided for the most part. If you want to manipulate the exhaust gases you do it in the header.

So what is actually going on, BOOM goes your fuel and air. Then a wave of gas hits the header at 1600 feet a second.
Then the hot and ever expanding gas hits your collector.. it now moving at 300 feet a second. Prize to the first person
to email me that in MPH. From the collector on the speed of the gas is determined by the catalytic convertor, or lack of.
The size of the exhaust pipe, how many bends, and last but not least how much your muffler balances out sound to flow.

Now for my point.. the first foot and a half from the port to the collector exit is what matters. We see 1600 feet a second,
hit a brick wall and goto 300 or less. Yet we see people spending $1800 dollars on an exhaust with a stock header.
This is a lack of understanding which i hope to address in education. If you focus on what matters, you will lose focus on what doesn't.