OK we all know that there is a damn midpipe thread every 10 min on Mustang Forums, so i thought why not have 1 thread for all the crap. Maybe sticky worthy?

OK here we go...
What they do

Basically as with any aftermarket exhaust piece mid-pipes increase the flow of exhaust and provide a better tone to the exhaust(make it louder)

H vs. X

H pipes give you the low rumble muscle car sound.
X pipes give a very throaty sound with a great raspy touch.

X-pipes do generally yield a little more HP, but not enough to make a noticeable difference.

Different types

H and X pipes both come in off-road and street legal.
The off-road pipes lack the catalytic converters thus increasing performance a bit. But as with all good things these off-road pipes are not always legal in every state.
Also there is a short midpipe and a long. the short midpipe is used when long tube headers are installed because the headers are just that, longer!

AND for the last time
No midpipe is THE BEST you just need to listen to soundclips!!!! Probable one of the best on THIS site it HERE
Feel free to add on or correct me on anything. I wrote this up real fast so i proble missed some.

 

you forgot the BEST MIDPIPE!!!! MAC Prochamber!!! haha well i like it...more of an H sound but very smooth and between the X and H HP wise....ive looked down inside mine and it seems like an X pattern inside of a box hints the X power and the H sound.

MAC has stopped making them in a catted version so they are O/R only now

 

good good keep it comin

 

Typically you want to pair H pipes with chambered mufflers such as Flowmasters and Mac. X pipes typically pair well with straight-through design mufflers such as SLP Loudmouths and Magnaflow Magnapacks. This is not the written rule as there are many different combos but this is the usually the standard way to go. And O/R midpipes are louder compared to the catted versions.