Everything You Need To Know About Your Mustang's Exhaust

I’m sure many of us are familiar with the “air pump” analogy – that is, an engine is essentially a big air pump, and the faster we move air into and out of the engine, the more power it will make. Therefore, replacing your factory exhaust with a larger, freer-flowing aftermarket exhaust can improve horsepower and torque.

Long-tube headers can also be called full-length headers, and require a shorty mid-pipe, oxygen sensor extensions, and a tune. Stock manifolds restrict airflow, especially on 2-valve engines. Tuning is required because long tube headers relocate the oxygen sensors further down-stream than factory, so a tune is necessary to compensate for the delay in response. For all you track-rats out there (or anybody who’s looking for a little extra kick from your pony) – long tubes are the way to go. Shorty headers are a direct replacement for your factory exhaust manifolds and do not require additional parts or tuning. Power gains differ between the two as well; long tubes will see the most gains in the mid-low to mid-high RPM range, while shorty headers will see their biggest gains in the mid-RPM range. Shorty headers are a great upgrade for your daily driver, but long tubes are best if you’re going for all-out performance, on the street or the strip. Another option for your Mustang headers is ceramic coating, which is more durable than chrome and absorbs heat better.

Mid-pipes come in 4 flavors – they are either X-pipes or H-pipes and come in standard length and “shorty” length. The “X” and “H” refer to the shape of the pipe, and which length you need depends on what headers you have on your Mustang. As I said above in the header section, long-tube headers require a “shorty” mid-pipe whereas shorty headers require a standard-length mid-pipe. If you don’t have aftermarket headers and are looking to upgrade your mid-pipe, the standard-length pipe is what you’re looking for. A Mustang X-pipe provides slightly more horsepower than an H-pipe, because it provides the “path of least resistance” for the exhaust gas to travel; but X-pipes often lend a higher-pitched, raspy note to the exhaust sound. Mustang H-pipes encourage the exhaust gas to “tumble” more, which gives H-pipes more of a rumble, with a slightly deeper tone. Ultimately, sound is a matter of opinion and some folks will sacrifice a few hp for a sound the prefer whereas others make hp their priority.

The mid-pipe is also where the catalytic converters are located, and most mid-pipes are offered “catted” and “off-road”; if your state requires a vehicle emissions test then we strongly recommend using a catted mid-pipe. Notice I haven’t mentioned anything about running straight-pipes from the headers to the back of the car – the reason is that this is not good for the engine’s performance. Mustang exhausts were designed with a crossover for a reason; the crossover helps to equalize exhaust pulses and back-pressure between the two banks of the engine, and it’s vital to maintain the crossover to keep your engine running correctly.

The section of the exhaust known as the cat-back contains the mufflers and runs from the mid-pipe back to the tail-pipes. There are a few things to keep in mind when you’re looking for a cat-back exhaust. Ford used 2 1/2″ piping that reduces to 2 1/4″ for most exhausts, whereas aftermarket pipes are 2 1/2″ throughout. Make sure you check the specs for each manufacturer, though, because some use a 2 1/2″ tip and some manufacturers offer kits with a 3″ tip, instead. Your Mustang’s mufflers are the biggest determination of your Mustang’s exhaust sound; there are basically two types – chambered and straight-through (aka – resonators). Chambered mufflers route the exhaust gas through a system of chambers and passages to muffle the sound. They are slightly more restrictive, but offer a quieter sound. Straight-through mufflers, or resonators, route the exhaust gas straight through the center of the muffler and are extremely loud. Each cat-back has a unique sound (depending on the manufacturer, muffler type, and presence of cats), so check some videos out online before making your decision.

If you’re looking for a more aggressive sound, you’ll want to convert to a true-dual exhaust. AmericanMuscle offers V6 Dual Exhaust Conversion kits in catted and off-road varieties that allow you to use a GT cat-back, giving you more cat-back options to choose from. Many V6 owners are concerned with the dreaded V6 drone, or installing an aftermarket exhaust and ending up with a Mustang that sounds more like a Mini. If you want don’t want that raspy, high-pitched sound and possible drone, avoid straight-through mufflers and resonators. Converting to a true-dual system will give you a much better sound than just installing aftermarket mufflers.

Alright folks, that’s all the time we’ve got for today! Tune in next month to see what’s new in the world of Q&A with Heather, and remember – if you have any questions that weren’t answered this time around, you can call or email us and one of our Mustang experts will be able to help you out.