Description
Overview
The Flowmaster American Thunder Cat-back Exhaust System is engineered to bring bold sound and improved performance to the 2004-2005 Dodge Ram 1500 equipped with the 5.7L Hemi engine. Designed as a complete bolt-on upgrade, this American Thunder system replaces the restrictive factory exhaust from the cat-back rearward, unlocking better flow and delivering the unmistakable deep, aggressive tone Flowmaster is known for. Built to fit all wheelbases, it’s a purpose-designed match for the Hemi-powered Ram.
At the heart of the kit is the legendary 50 Series HD single in/out muffler, tuned to produce a moderate sound level that stays refined at cruise yet delivers a rich, powerful growl under throttle. The result is a deep, moderate tone both inside and outside the cab — strong and satisfying without becoming overbearing on long drives.
Engineering & Construction
Every component is manufactured from durable 409S stainless steel for lasting corrosion resistance and strength. The system uses a 2.75-inch to 3.00-inch adapter pipe that steps up flow into the 50 Series HD muffler, then feeds a single 3.00-inch mandrel-bent stainless steel tailpipe. Mandrel bends preserve a smooth, consistent diameter throughout the tubing, promoting efficient exhaust flow. The tailpipe exits on the passenger side behind the rear tire and is capped with a polished 3.50-inch stainless steel Flowmaster tip for a clean, finished appearance.
Key Benefits
- Improved horsepower, torque, and mileage from the freer-flowing cat-back design
- Deep, moderate sound level tuned by the proven 50 Series HD muffler
- 409S stainless steel construction for durability and corrosion resistance
- 3.00-inch mandrel-bent stainless steel tailpipe for smooth, unrestricted flow
- Polished 3.50-inch stainless steel Flowmaster tip for a finished look
- CARB (California) compliant — Emission Code 5
Fitment
This American Thunder system is application-specific for 2004-2005 Dodge Ram 1500 trucks with the 5.7L Hemi engine, and it fits all wheelbases. It’s configured for 4WD applications with a single passenger-side exit. The muffler is included as part of the complete kit (Muffler Part Number: Kit Only), while no heat shield is included.
Installation
Installation is straightforward thanks to the bolt-on design. The kit ships with detailed instructions and all the necessary hardware, making it a manageable upgrade for those comfortable working under their truck. Backed by Flowmaster’s Lifetime Limited Warranty, this cat-back system offers lasting confidence along with its performance and sound gains.
Please note this product carries a California Proposition 65 warning. If you’re after a genuine Flowmaster upgrade that adds performance, an aggressive tone, and stainless steel durability to your Hemi-powered Ram, the American Thunder Cat-back System delivers on all fronts.
