nhk

cat = Catalytic converter
supercat = high flow Catalytic converter
cat back = the system after catalytic converter
mid pipe = after cat but before the muffler
cat back including = mid pipe and muffler.
header /extractor= between cat and exhaust port of engine

Hope I am not wrong w this info

lurch519

aftermarket exhaust = any exhaust system not manufactured or marketed by mazda
cat back exhaust = exhaust system that consists of the piping from the cat (catalytic convertor) to the exhaust tips
mid pipes = for the 8, this refers to the section of pipe including the cat, so this should actually be referred to as a cat delete pipe
supercat = high flow cat

TeamRX8

iTrader: (25)

the Mazda OE exhaust has four pieces; the exhaust manifold, the catalytic converter section, a midpipe, and a rear muffler. Once the OE midpipe and OE rear muffler are joined together they are not intended to come back apart from each other. It will never seal properly again if you do.

There are aftermarket headers to replace the OE exhaust manifold. Not much power to be gained there, just some weight loss.

Some of the confusion comes in because the aftermarket replacements for the OE catalytic converter section are referred to as a midpipe. This is not the same piece that Mazda calls a midpipe. The OE piece has both a catalytic converter and a resonator muffler in it. The aftermarket replacements come with or without a cat converter, usually a "high flow" converter if it does, and with or without a resonator muffler. No cat and/or no resonator = much louder than OE, especially with a loud aftermarket muffler system. This section will yield the most power and engine response and some weight loss too. Supercat is just one suppliers name for their aftermarket high-flow cat converter section. A midpipe without a cat converter is not emissions legal, it is intended as an off-raod racing piece only, depending on your character and situation.

The joined OE midpipe and OE rear muffler section is replaced with an aftermarket cat-back exhaust system. The aftermarket systems usually have a bolted flange where the OE midpipe and OE rear muffler are permanently clamped together, so the aftermarket system can be taken apart and easily shipped while the OE one cannot. OE exhausts are usually given away for free just to get rid of them. There's very little power to be gained with the cat-back muffler systems. The lightest ones can knock off the biggest amount of weight from the exhaust system, but are also typically the most expensive (titanium=$$$). Sound can range from barely louder than OE to "can't hear yourself think inside the car" depending on all of the above combinations.

This picture shows the OE catalytic converter section, the OE middle pipe, and the OE rear muffler



Hope that helps.

epitrochoid

my cat back seals up to my cat just fine. i don't know where you got that from, but i've never heard of anyone getting a leak there

TeamRX8

iTrader: (25)

you misread, I was referring to where the OE middle pipe connects to the OE rear muffler (shown as the circled "Y" points on both in the picture above), thanks for clarifying my comment about why & how people get confused between the OE and aftermarket terminology regarding the mid pipe, they are not the same thing

Nemesis8

iTrader: (3)

What exactely are you trying to accomplish? Different exhaust note? Less weight? etc...