The best Flowmaster exhausts in this collection are application-specific cat-back systems: the American Thunder dual rear exit system for the 2013-2019 BRZ, 2013-2016 FR-S, and 2017-2019 86, and the dBX single rear exit system for the 1990-1997 Mazda Miata. If you want a bolt-on cat-back with a distinct Flowmaster sound, start with the system for your exact year and model.
A cat-back replaces the piping, muffler, and tips from the catalytic converter rearward, which is where most of a car's exhaust note is shaped. Look first at fitment: platform, year range, and exit style all differ between the two systems here, so the BRZ/FR-S/86 car and the NA Miata use entirely separate systems. Then consider layout — the Miata dBX is listed in 409S with a single rear exit, while American Thunder exits through dual rear outlets. Browse the wider platform catalogs in 2013+ BRZ/FRS/GT-86 and 1990-1997 Mazda Miata (NA) Parts alongside this collection.
Flowmaster American Thunder Cat-Back for BRZ/FR-S/86 is the headline system here, a dual rear exit cat-back covering three closely related rear-wheel-drive coupes across the years listed in its title. Flowmaster built its reputation on muffler-driven sound tuning for American performance cars, and its named series such as American Thunder and dBX let buyers choose a system by its intended sound character rather than by pipe size alone. Here that approach shows up in two focused import applications, so the exact year and model in each title matters.
The second system, the Flowmaster dBX Cat-Back for the 1990-1997 Miata, applies the same complete-system idea to the first-generation roadster, with a single rear exit in 409S. Buyers cross-shopping exhaust brands should also consider MagnaFlow, known for stainless cat-back systems with a smooth, deep tone and a broad sport-compact catalog. Borla takes a sportier, sharper approach to exhaust sound and organizes its systems by sound level, which makes it a useful comparison for drivers weighing volume. Gibson is another application-specific cat-back name in the store, concentrating mainly on truck systems built around exact cab and bed configurations. For background before you buy, read our guide on why enthusiasts upgrade their exhaust systems.
Which Flowmaster system fits my car?
Choose by the title: the American Thunder system covers the 2013-2019 BRZ, 2013-2016 FR-S, and 2017-2019 86, while the dBX system covers the 1990-1997 Miata. Check your year and model carefully, because the two systems do not interchange.
Does a cat-back exhaust require a tune?
A cat-back changes piping behind the catalytic converter and is designed to work with the factory calibration for the systems listed here. No tune is required for the exhaust itself, though you should follow the product listing for your application.
How difficult is a cat-back installation?
Cat-back systems are bolt-on designs that use factory hanger locations, so installation is a common garage job with the car safely raised. Old, heat-cycled hardware can be stubborn, so penetrating oil and a second pair of hands help with alignment.
What is the difference between American Thunder and dBX here?
In this collection, American Thunder is the dual rear exit system for the BRZ, FR-S, and 86, while dBX is the single rear exit 409S system for the 1990-1997 Miata. The practical difference starts with fitment, then exit layout and sound character.
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