Description
Overview
The Flowmaster American Thunder Cat-back Exhaust System is built for the driver who wants the classic look of a traditional dual exhaust system combined with all the real-world performance benefits of a genuine Flowmaster Cat-back. Engineered around the acclaimed Super 40 Series muffler, this American Thunder system delivers a moderately aggressive exterior tone paired with a controlled, moderate interior tone — so you get an unmistakable presence outside without an overbearing drone in the cab.
Every component is designed to work together. The system is constructed from mandrel-bent 2.50-inch aluminized steel, keeping exhaust flow smooth and unrestricted from the cat-back all the way out. That efficient flow feeds into the specially designed Super 40 Series muffler and finishes with dual 2.50-inch tailpipes capped by polished 3.00-inch stainless steel tips for a clean, muscular appearance.
Key Benefits
Like all Flowmaster systems, the American Thunder is about more than sound. The freer-flowing, mandrel-bent design is built to improve throttle response, power, and mileage, making it a smart upgrade for daily driving, hauling, and everything in between. Because the system uses the factory hanger locations and includes all necessary parts and hardware, installation is straightforward with U-Bolt clamping for a secure, no-guesswork fit.
Choose Your Tailpipe Exit
You can tailor the American Thunder to how you use your truck. Select tailpipes that exit straight out the back for a bold, muscular look, or choose the configuration that exits behind the rear wheels — an ideal setup for towing. Either way, you get the same dual-outlet styling and polished stainless tips.
- Mandrel-bent 2.50-inch aluminized steel construction for smooth exhaust flow
- Super 40 Series muffler tuned for a moderately aggressive exterior and moderate interior tone
- Dual 2.50-inch tailpipes with polished 3.00-inch stainless steel tips
- 3.00-inch inlet diameter and U-Bolt clamping type
- Muffler included; heat shield not included
- CARB (California) compliant, Emission Code 5
- Backed by a Flowmaster 3-Year Limited Warranty
Fitment
This American Thunder system is designed for 4-wheel drive (4WD) applications only, specifically with the extended cab / short bed configuration. Always confirm your vehicle’s cab and bed setup before ordering to ensure the correct fit.
If you prefer full stainless steel construction and a Lifetime Limited Warranty, consider Flowmaster exhaust system part #817473 as an alternative. Otherwise, the American Thunder Cat-back delivers the traditional dual-exhaust look, aggressive-yet-livable sound, and proven Flowmaster performance in an easy-to-install package with everything you need in the box.
