While there’s no denying the performance benefits that came with the later S197 Mustangs, the tried-and-true 4.0 liter V6 and 4.6 liter V8 engines definitely have a loyal fanbase. That’s with good reason too. These cars are easy to customize and enhance. The Mustang GT’s 3-valve modular V8, especially, has lots of performance potential in an extremely reliable platform.
Just as notably, it also has an amazing, nostalgic exhaust note. Say what you will about the Coyote, but there’s just something about the 3-valve rumble that gives the pre-refresh S197 GT cars a special sound. To fully take advantage of your exhaust system, you'll need to find the best aftermarket upgrades for your set-up. Whether you want a custom exhaust note, improved performance, or both, there are tons of options for every enthusiast. And while the V8 is famous for its great noise, you’ll also find a lot of great choices for the V6 as well.
While packages like the California Special offered bright-rolled exhaust tips, you'll have to turn to the aftermarket to get some serious upgrades for your S197's exhaust system.
If you do have one of the refreshed S197s, you’ll want to check out this 2011-2014 Mustang exhaust guide, as the newer configurations require different products and modifications.
2005-2010 Mustang Axle-Back Exhaust
If you really just want to upgrade the acoustic output of your Mustang, an aftermarket axle-back exhaust system will offer the best bang for your buck. You won’t see the noticeable performance benefits of something like a cat-back exhaust or headers, but you’ll get an affordable and easy-to-install way to customize your exhaust note. There’s no need to do any cutting or welding for most axle-back kits, making this a simple project for just about anyone to complete in their garage. Plus, some new custom exhaust tips will add a nice finishing touch to your Mustang’s rear end.
Whether you have a V6 or V8, you can swap out your quiet factory mufflers for an aftermarket axle-back system that will give you the sound you’ve always dreamed of. From a rich, low rumble that sounds like a classic muscle car to an aggressive, race-inspired roar, you can choose a kit that will be the ideal sound character for your build.
2005-2010 Mustang Cat-Back Exhaust
For a more comprehensive upgrade, you can consider adding a cat-back exhaust system. While you’ll typically have to spend more than for an axle-back, you’ll be taking things to the next level in terms of both sound and performance. Moreover, you likely won’t have to do any cutting or welding, because you’re replacing so many components in one fell swoop.
With an aftermarket system, you’re able to swap out your restrictive OEM parts for some free-flowing pipes that offer demonstrable gains in power. By ditching your quiet stock mufflers, you’ll also be able to give your Mustang the sound profile that it truly deserves.
2005-2010 Mustang Headers
To truly get the most out of your exhaust system when it comes to airflow efficiency and power, you’ll want to swap out your restrictive stock intake manifold with some aftermarket headers. Although these underhood components won’t offer quite as much in the way of enhanced acoustic character or visual style (until you pop your hood), they’re a virtual necessity for maximizing your overall horsepower and torque.
You can choose between long-tube and shorty headers for your S197 Mustang. You’ll almost certainly want to opt for shorty headers if you’re using a turbocharged set-up or a have a low ride height; these smaller components are also easier to install in general. Long tube headers, on the other hand, will offer louder sound and a larger power increase, due to their free-flowing design. For a full breakdown on the topic, check out our guide on the different types of headers for your Mustang.
2005-2010 Mustang Mid-Pipes
If you want a more affordable option compared to most cat-back systems, you can look into swapping some new mid-pipes into your S197. Cutting and welding will be required, so it’s important to keep that in mind if you don’t have the technical background to tackle that on your own.
In terms of benefits, a new set of H-pipes, X-pipes, or Y-pipes will grant your Mustang better exhaust airflow, minimizing engine back-pressure and increasing horsepower. Plus, depending on your choice of set-up, you’ll enjoy some nice sound enhancement as well.
Additional S197 Mods to Pair with Exhaust Upgrades
Don’t forget about the other two components of the arguable Mustang performance trifecta; in addition to an overhauled exhaust system, it’s well-worth adding a performance cold air intake and custom electronic tune. Used in conjunction, this is one of the most cost-effective and realistic ways to truly optimize the performance of your pony. If you’re a beginner or journeyman wrencher, you should have few issues doing all of the installs yourself.
To go further beyond the performance levels that these three upgrades offer will typically require the addition of a supercharger...and that’s an entirely different ballgame that will ask a lot out of even the most seasoned gearheads.
Image Credit: Ford Performance