There have been a lot of posts about which exhaust is better etc.... so I was asked to help clear things up and give you a run down of all the exhaust systems and what they do. This is not meant to be an "all inclusive" thread, but merely to provide some basic information to both beginners and those that just need a review.

We start at the back with the "Catback" this is the part of the exhaust system that is after the cats. There is some hp to be found here, not a lot, but every bit counts when you want to go fast. Also the stock piping for 96+ 2valve and 4valve cars is 2.25 inches. Most aftermarket catbacks are 2.5"

Catbacks-
There are 2 different kinds of mufflers for your catbacks: chambered and straight-through. The chambered setups use baffles to direct airflow and makes a deep "old school" sound. This is what flowmaster, mac, and others use. Then we have straight through such as the magnaflow, dynomax, Slp etc.. This a higher pitch sound but does not drone like chambered setups. Both add hp. How much really depends on the rest of the exhaust setup and the power that the motor is making. Generally speaking, straight-through designs have more potential. BUT, you may end up making less power if you don't do your homework.

Mid-pipes-
Mustangs have mid pipes which is the part of the exhaust system that connects the headers to the catbacks commonly called the "Mid-pipe". From the factory, late modle Mustangs are equipped with 2.25 inch "H-Pipes" with 4 cats (some california cars may have 6 cats).

There are three options for mid-pipes: H-pipes ,X-pipes, and Prochambers.

The H-pipe is shaped like an "H" and is what is supplied from the factory. They are 2.5" when stock, so most after-market ones are 2.5" and there some 3" ones. Larger mids are not really needed until you push high HP numbers. The H-pipe gives you low to mid range power. They add more torque and Hp in the lower rpm ranges than the x-pipe or prochamber. But they make less power in the high rpm ranges then other options. Some think that they make the "old school" muscle car sound.

Next we have the X-pipe. An X Pipe eliminates the H-pipe design and uses an X shape to balance the exhaust gases. This gives more high-end power. They come in 2.5" and 3" sizes also. But again, the 3" is really not needed. They provide a more "European" sound or even an "exotic" sound. Generally, the note is more high pitched.

Then we have the Prochamber. This is made by Mac to help give a choice between the H and X pipes. Prochambers claim to give the best of both words. It has a exhaust note kind of like the x-pipe. They are also available in 2.5" and 3" setups.

Now with all of these "mid-pipes" you can get them in either a catted or non-catted version. Catalytic converters or "Cats" are used to clean the exhaust gases and prevent polution. If your state does not do emission testing like here in florida you can geet away with running an "Off-Road" version of a mid-pipe. This is a mid-pipe without cats. By not having cats the motor has less restrictions and will make more power than a catted pipe will. Not having cats will also raise your exhaust noise level a lot. You can also experience a loss of power by removing your cats depending on the entire exhaust setup and the power output of the engine.

Headers-
Stock, Mustangs are equipped with "exhaust manifolds". They are small and restrictive you can gain power by getting rid of them. There are 3 different kinds out there. Long tube headers, Short tube headers, and Mid length headers.

Short-Tube Headers are setup to be used with stock mid pipes so you don’t have to modify or replace the mid pipe. They come in equal length and unequal length. The equal length are said to help exhaust flow and give a touch more power than unequal length headers. As the equal length headers use the same length of tubing for all the exhaust gases to travel through in the header. These give least power of the 3 headers. But are good for people who need to stay legal but want more power.

Mid Length Headers will require a mid-pipe exchange to accomodate them. They are a compromise of the long-tube headers and short-tube headers. They give you more exhaust tubing in the header so it helps the exhaust gases flow faster but they are not as long as the long tubes so ground clearance is not a problem with them. They give more power then short tubes and a bit less than long tubes.

Long-Tube Headers are the bad boys. They give the most power of all the header setups, but are harder to install and need a mid-pipe made for long tubes. The headers use normally 30" of header tubing to make each cylinder have as much free space as possible to go so they can make more power. These headers will reduce ground clearance as they hang a bit lower than short tube headers or mid lengths. But if you want all out power these is what you want.

 

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