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The Sound That Started it All

American Thunder® is the ‘original’ Flowmaster sound. In most cases a very aggressive sound level, American Thunder systems use various chambered mufflers to achieve the performance gains and aggressive sound that you want from your car or truck, inside and out. Available in stainless steel or economical aluminized steel, American Thunder systems are a great choice when you want to be heard.

Features

  • Aggressive Sound Exhaust Tone
  • Mandrel Bent 16 Gauge Tubing
  • Axle-Back, Cat-Back, or Header-Back Systems
  • Includes Hangers and Hardware for Easy Installation
  • Dyno Tuned for Maximum Performance
Flowmaster American Thunder Cat-Back Exhaust Install for 2021-2022 Ford Bronco
Flowmaster Exhaust Buyer’s Guide For The 2021-2022 Ford Bronco
Flowmaster's Exhaust Systems For The New Ford Bronco Step Up Performance On And Off-Road
Installing Flowmaster's American Thunder Dual Exhaust System For 1964-1972 GM A-Bodies
What Is Exhaust Drone, And How Flowmaster Can Help You Prevent It
Flowmaster Releases American Thunder Stainless Steel 2.5" Dual Exit Header-Back Kit For 1967-72 Ford F-Series Trucks!
Flowmaster American Thunder Exhaust Installation for 67-72 C10 Trucks
American Thunder Cat-back Exhaust for 2020 GM Silverado/Sierra 2500HD/3500HD 6.6L
American Thunder Exhaust for 2014-2019 RAM 3500 with the 6.4L Hemi
Add Some Muscle to your 5.7L Hemi RAM 1500
Some American Thunder for your 2020 Jeep Gladiator
Flowmaster American Thunder Exhaust with Exclusive W.A.V.E. Technology for your Mustang GT
Install some Thunder on your 2018-2019 Ford Mustang GT w/5.0L
Add some Thunder to your 2013-2015 Toyota Tacoma 4.0L
Flowmaster American Thunder Cat-back Exhaust for 2009-2019 Toyota Tundra Trucks
2019 Chevy Silverado & GMC Sierra 1500 5.3L - American Thunder Cat-back Exhaust
Flowmaster Releases Cat-Back Exhaust Systems For GM, Ford & Nissan Trucks
Delta Force Performance Air Intake & American Thunder Axle-back for 2010-15 Camaro w/3.6L
Flowmaster American Thunder Cat-back Exhaust - 2019 GM 1500 with 6.2L
Flowmaster American Thunder Axle-back & Scavenger X-Pipe for 2016-2018 Camaro SS/ZL1 w/ 6.2L Engine
Dyno Tested: Flowmaster American Thunder Cat-back Exhaust and Delta Force Intake
Flowmaster American Thunder Axle-back Exhaust for 2018 Jeep Wrangler JL, 2-Door
Flowmaster American Thunder Cat-back Exhaust for 2019 RAM 1500 Trucks w/ 5.7L
MORE POWER: Flowmaster Intake, Exhaust, and Tuner on a 2018 Ford F-150 3.5L EcoBoost
Flowmaster American Thunder Cat-back for the 2014 - 2017 Ford Fiesta ST
Tech Tip: Comparing Flowmaster Outlaw, American Thunder, and Force II Exhaust Systems
Flowmaster American Thunder Axle-back Exhaust for 2018-2019 Ford Mustang GT 5.0L
Flowmaster American Thunder Cat-back Exhaust 2015-2018 Dodge Charger SRT 392, Scat Pack & Hellcat
Flowmaster Factory Tour and Chevy Silverado American Thunder Cat-back Install
2011-18 GM Silverado/Sierra 1500 6.2L - Flowmaster American Thunder Cat-back Exhaust
Flowmaster American Thunder Dual Mode Axle-back Exhaust (NPP) 16-18 Camaro SS & ZL1 6.2L
Flowmaster American Thunder Axle-back Exhaust System for the 16-18 Camaro LT 3.6L V6
1986-04 Ford Mustang GT, LX and Cobra 4.6L or 5.0L V8 - Flowmaster American Thunder Cat-back Exhaust
Flowmaster American Thunder Header-back Exhaust for 68-70 Mopar B-Body
2015-18 Ford Mustang 2.3L, 3.7L, Flowmaster American Thunder Axle-back Exhaust
1994-01 Ram 1500 5.2L, 5.9L - Flowmaster American Thunder Cat-back Exhaust
Flowmaster American Thunder Cat-back Exhaust System - 2015-2016 Dodge Charger R/T w/5.7L V8
2016-18 Toyota Tacoma 3.5L, American Thunder Exhaust System
2015-16 Dodge Challenger R/T 5.7L, American Thunder Cat-back Exhaust System2015-16 Dodge Challenger R/T 5.7L, American Thunder Cat-back Exhaust System2015-16 Dodge Challenger R/T 5.7L, American Thunde
Flowmaster American Thunder Axle-back Exhaust System - 2016-2018 Camaro SS
2015-19 Ford F150 5.0L TiVCT Flowmaster American Thunder Cat-back Exhaust
American Thunder Cat-back Exhaust - 2015-19 Ford F150 - 2.7L Ecoboost
Flowmaster American Thunder Cat-back Exhaust System 2015-2019 Ford F150 3.5L Ecoboost
Flowmaster American Thunder Cat-back Exhaust System 2015-2019 Ford F150 3.5L TiVCT
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Sound Level
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Material
  • 409 Stainless Steel
  • Aluminized Steel
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  • Axle-back
  • Cat-back
  • Crossmember-back
  • Direct-Fit Muffler
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Tubing Diameter (in)
  • 2.25
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    American Thunder

    The classic sound of a Flowmaster® chambered exhaust, our American Thunder® Series features mufflers tuned to deliver more power, torque, throttle response and mileage. Best of all, these exhaust systems take sedate vehicles and delivers a deep aggressive tone.