Description
Overview
The Flowmaster American Thunder Cat-back Exhaust System is built for the enthusiast who wants the aggressive look and voice of a NASCAR race truck combined with all the benefits of a genuine Flowmaster cat-back. Engineered as a D.O.S.S. (Dual Out Same Side) configuration, this American Thunder system delivers a moderate-to-aggressive tone that makes itself known inside the cab and out on the street, so your performance can finally be heard.
At the heart of the kit is a Super 40 Series performance muffler, tuned for a deep, powerful sound that hits hard without droning into harshness. Exhaust gases move through 3.00-inch mandrel-bent aluminized steel tubing, then split into dual 2.50-inch tailpipes finished with a pair of 3.00-inch polished stainless steel tips for a clean, high-quality look at the exit.
Key Benefits
Mandrel-bent tubing preserves diameter through every bend to keep flow smooth and consistent, while the aggressive Super 40 Series muffler gives the truck a purposeful, race-inspired attitude. The dual-out-same-side layout provides that unmistakable NASCAR-style appearance, and the polished stainless tips add a finishing touch that stands up to the elements.
- American Thunder series with a moderate-to-aggressive interior and exterior tone
- Super 40 Series performance muffler included for a deep, powerful sound
- 3.00-inch mandrel-bent aluminized steel tubing for consistent flow
- Dual 2.50-inch tailpipes with a pair of 3.00-inch polished stainless steel tips
- D.O.S.S. (Dual Out Same Side) design for a NASCAR race-truck look
- Includes all necessary hardware and instructions
Sound & Performance
The Super 40 Series muffler is what gives the American Thunder its signature character — an aggressive, unmistakable Flowmaster growl at throttle that settles into a confident cruise. Paired with the free-flowing 3.00-inch inlet and mandrel bends, it’s a system designed to look, sound, and perform like a truck built to be driven hard.
Fitment
This cat-back kit is designed to fit both 2- and 4-wheel-drive models in a standard cab / short bed configuration on a 119-inch wheelbase. It ships as a complete kit with the muffler included, plus all mounting hardware and detailed instructions to guide installation. Please note this is an emissions-related product carrying a California Proposition 65 warning; the system is CARB (California) compliant with Emission Code 5.
Backed by a 3-year Limited Warranty, the Flowmaster American Thunder Cat-back is a proven upgrade for drivers who want their build heard and seen. Choose it to transform the sound and stance of your truck with hardware engineered by one of the most recognized names in performance exhaust.
