It can be tough to get the exhaust sound you want out of a four-cylinder engine. While the 2013-2018 Focus ST’s turbocharged powerplant offers plenty of performance for a hot hatch, the small displacement means that it doesn’t offer much in the way of an exhaust note. The restrictive factory system keeps things pretty quiet, in addition to reducing overall potential for more power. By increasing airflow, the reduced backpressure and faster expelling of gases can give you a small but noticeable bump in horsepower and torque.
That’s why aftermarket exhaust upgrades are so popular within the Focus ST enthusiast community. Drivers are able to get the exhaust note they really want, whether that’s a smooth growl or a race-inspired roar. Plus, when used in conjunction with an electronic tune and/or cold air intake, you can see even larger gains in terms of horsepower and torque.
If you already know what you’re looking for, head on over to check out our full selection Focus ST exhaust parts. If not, this guide can serve as a great starting point or source of inspiration to help you figure out which type of exhaust kit will work best for your Focus.
Focus ST Axle-Back Exhaust
If you’re looking primarily for an easy way to get a different exhaust note without quite as many of the performance benefits, you can check out an axle-back exhaust kit. It’s a simpler install than a cat-back exhaust kit, as you’re only replacing the parts behind your rear axle (the muffler and exhaust tips).
While they’re not as popular for the Focus ST as they are for cars like the Mustang, getting rid of the factory muffler can add an aggressive sound that many drivers are looking for. At its core, an axle-back exhaust upgrade will mostly serve as a muffler delete for your Focus ST, while also giving you new exhaust tips.
Options like this MRT Eco-Flow axle-back can offer some great sound at an affordable price. We really like the balance it strikes, giving a sporty, race-inspired growl that doesn’t stray too low or high in terms of pitch. Plus, you can get the style you want by selecting either polished stainless steel or matte black exhaust tips.
Unlike an axle-back, a cat-back exhaust for your Focus ST will replace the entire system, including mufflers, exhaust tips, and the intermediate mid-pipes. With the removal of the original factory resonators, you can enjoy a much more noticeable sound note from the 2.0 liter EcoBoost engine, while also unlocking more of its true performance potential. Let’s take a look at some of the different types of cat-back exhaust options.
Focus ST Touring Exhaust Kits - A Subtle Upgrade from Stock
For those that want an exhaust system that’s louder than stock but not too brash, touring exhaust kits offer a nice step-up from factory. You won’t have to worry about the exhaust drone that can occur with more aggressive upgrades, but you’ll still enjoy a nice change in tone and volume.
The Ford Performance exhaust is one of our favorites of the quieter exhaust kits, especially because it stays below the 95-decibel California standard. The Borla Touring cat-back has a deep, rich sound and allows some of the turbo noises to be heard as well, making it a very popular choice for enthusiasts. AWE offers some fantastic options as well, with their patented drone-canceling technology available in both resonated and non-resonated cat-backs. The non-resonated options are closer to a track-style exhaust system, giving you even better performance and a higher noise level.
Focus ST Sport Exhaust Kits - Increased Sound and Power
There’s not really an official term for these “medium-level” exhaust kits, but we’ll call them “sport” for simplicity’s sake (you could also call them “street”). They offer a nice balance between touring and track systems, serving as a great option for those who want improved performance and sound, while still maintaining a very livable level of daily drivability.
The Roush cat-back is a very popular choice, and with good reason. It has a performance-flow muffler, offering great performance and a sporty, balanced sound. Another great option is COBB’s cat-back, which also has a rich tone. It’s probably on the louder side compared to many of these other street systems, making it a great choice for those that want more volume, but aren’t looking for something quite as loud as a track exhaust.
Focus ST Track Exhaust Kits - Loud and Performance-Oriented
For the weekend racers out there, these are the loudest and most track-focused exhaust kits available. You’ll definitely want to check your local and state laws regarding sound, as you very well could be restricted to off-road track use only. But if that’s how you use your Focus ST and you don’t need it as a daily driver, these all-out exhaust kits might be just what you’re looking for.
The biggest difference between track exhaust kits and the earlier ones we mentioned is that they are typically in what is called a “straight-piped” configuration, with no real muffler or resonator to speak of (usually just a tunnel resonator muffler). If there is a muffler, it is much, much less restrictive than the factory one.
The AWE track system will give you maximum sound and performance from your car, but is still a simple bolt-on installation. It won’t trigger your “check engine” light either. It provides an aggressive sound that is deep but still has a bit of rasp to it. The Accelatec track cat-back is another excellent option, with an exhaust note that is loud and snarly without being too overwhelming.
No matter what kind of sound you’re looking to get out of your Focus ST, you’re sure to find a cat-back system that gives you the exhaust note, volume level, style, and performance that you want. From moderate upgrades for your daily driver to the track-focused exhaust you want for your weekend autocrosser, you’ll find a wide variety of exhaust kits for your Focus ST right here at CJ’s.