Description
Overview
The Flowmaster American Thunder Crossmember-Back Exhaust System is built for the enthusiast who wants their performance to be heard. This is a true dual crossmember-back system engineered to deliver a moderate to aggressive exhaust tone, both inside and outside the vehicle, without sacrificing everyday drivability. If you’re chasing that unmistakable Flowmaster sound backed by real performance gains, the American Thunder series answers the call.
At the heart of the system is a pair of specially selected Super 44 Series mufflers (muffler part number 842546), tuned to produce the deep, aggressive character that has made Flowmaster a household name among performance and truck enthusiasts. A built-in H-pipe crossover balances exhaust flow between the dual tail pipes for a smoother, more refined tone and consistent power delivery.
Construction & Performance
Every American Thunder system is constructed from 16-gauge mandrel-bent stainless steel tubing, ensuring smooth, unrestricted flow and long-lasting durability. The 2.50″ inlet diameter and dual tail pipe design work together to improve throttle response, power, and mileage — the core benefits you expect from a Flowmaster exhaust upgrade. Designed with an easy fit in mind, the system includes all hangers and hardware necessary for a straightforward installation.
Key Highlights
- True dual crossmember-back configuration with built-in H-pipe crossover
- 16-gauge mandrel-bent stainless steel tubing for durability and flow
- Pair of Super 44 Series mufflers (P/N 842546) for a moderate to aggressive tone
- 2.50″ inlet diameter with dual tail pipes in a silver pipe finish
- Includes all hangers and hardware needed for installation
- CARB (California) compliant — Emission Code 5
Sound Profile
The American Thunder series is purpose-built to deliver a moderate to aggressive interior and exterior tone. It strikes the balance between an assertive, performance-forward growl under acceleration and a manageable presence during cruising, making it ideal for the driver who wants attitude without excess.
Options & Configuration
This system is designed for 2WD applications and ships with the Super 44 mufflers included. Exhaust tips are sold separately, and a heat shield is not included, giving you the flexibility to finish the setup to your preference. If you prefer aluminized steel construction over stainless, Flowmaster offers an alternative in system #17129.
Compliance
This exhaust system is CARB (California) compliant with an Emission Code of 5, and carries a California Proposition 65 warning. Choose the configuration that fits your vehicle and driving style, and add the Flowmaster American Thunder tone to your ride.
