Free Shipping On Orders Over $49. Details

Talk to a Mustang Enthusiast
M-F 8:30A-11P, Sat-Sun 8:30A-9P
Win $6,000 In Store Credit Enter Now

Flowmaster American Thunder Cat-Back Exhaust (05-10 GT, GT500)

Item 18427
Call a Mustang Enthusiast at 1-877-887-1105
M-F 8:30A-11P, Sat-Sun 8:30A-9P
Market Price $949.14 You Save 12% ($109.19)
Our Price


FREE Shipping

Will this fit your Vehicle?

Select a different vehicle Help?
Update or Change Vehicle
In Stock

Ship to: Ashburn - 20149
Sorry, please enter a valid US or CA postal code
We're sorry, zip can't be updated at this time.
    Create a list
    Add to New List

    Saved - View your saved items

    We're sorry. We couldn't save this product at this time.

      Review & Installation Video

      Hey I’m Justin with and I’m taking a closer look at Flowmaster’s American Thunder series Cat-Back exhaust fitting the 2005-2010 Mustang GT, and GT 500. As you may or may not know, Flowmaster offers a wide variety of different mufflers, each with their own unique sound. In this case, the American Thunder centers around these two 60 series delta flow mufflers, which of course will still give you that iconic Flowmaster sound, but they’re not going to be as loud as Flowmaster’s 40 series mufflers. The American Thunder is constructed using durable 409 grade stainless steel, even including those 3 chambered 60 series mufflers. The system also features mandrel bends throughout, all exiting out these 4” polished tips, embossed with that Flowmaster logo. Getting this Cat-Back bolted up to your S197 is a very simple task, that should take you no more than 2 hours using basic hand tools. Now let’s hear how to Flowmaster American Thunder Cat-Back sounds compared to our factory exhaust.

      Product Information

      Features, Description, Specs & Installation


      • Aggressive Flowmaster 60-Series Delta Flow Sound
      • Durable 409 Stainless Steel Construction
      • 3" Mandrel-Bent Tubing
      • 4" Polished Stainless Steel Tips
      • Includes Scavenger X-Pipe and Two Flowmaster 60 Series Mufflers
      • Fits 2005-2010 GT, Bullitt, and Shelby GT500


      Signature Flowmaster Sound. Give your Mustang that unmistakable Flowmaster sound with the American Thunder Cat-Back Exhaust system from AmericanMuscle. The Flowmaster American Thunder Cat-Back Exhaust with its mandrel bent tubing will greatly improve your Mustang's exhaust flow for an increase in power. The included 60 Series Delta Flow Mufflers will improve your exhaust's sound for a deep aggressive exhaust note.

      Reuses Stock Cats. Installation of the Flowmaster American Thunder Cat-Back Exhaust requires cutting the factory H-Pipe to bolt up the new Scavenger X-Pipe directly behind the factory catalytic converters, making your Mustang 100% smog-legal.

      Race Car Growl.
      The included Scavenger X-Pipe not only helps increase power, but it also adds a loud raspy, race car growl to the sound of your exhaust with its modern "X" crossover pipe design.

      Quality Construction.
      Constructed from durable 3" 16 gauge 409 stainless steel tubing for it's corrosion resistant properties, the Flowmaster American Thunder Cat-Back features two 60 Series Delta Flow American Thunder mufflers with massive 4.0" diameter polished stainless steel tips for great muscle car looks and sound. As an added bonus, the tips are embossed with the "Flowmaster" logo for true custom styling.

      This Flowmaster American Thunder Cat-Back Exhaust System is designed to fit the 2005 to 2010 GT, Bullitt and the 2007-2010 Shelby GT500 Mustangs for both great looks and great sound.

      Shipping Note: This product can not be shipped to an APO/FPO, Guam, or US Virgin Islands addresses.

      Technical Note: Americanmuscle recommends adding the 2005+ Mustang 304 Stainless Steel Exhaust Hanger Kit from the drop down option above, to provide more strength, stability and a cleaner installed appearance. If you have a 2007 Mustang you may need the kit for correct installation.

      Fitment: 2005 2006 2007 2008 2009 2010 Details

      Flowmaster 817494

      CA Residents: WARNING: Cancer and Reproductive Harm -

      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (2) Muffler assemblies
      • (2) Over axle pipes
      • (1) Scavenger X-pipe Assembly
      • (4) Clamps

      Tech Specs

      Cat-Back Exhaust Specifications
      Piping Material:409 Stainless Steel Tip Material :Polished Stainless Steel
      Piping Size:3.0"Tip Size:4.0"
      Muffler Type:ChamberedFitment:2005-2010 GT, Bullitt and Shelby GT500

      Customer Reviews (100+)

        Reviews of Flowmaster Exhaust products have an average rating of 4.7 out of 5

          Questions & Answers

          10 More Questions

          Will It Fit My Mustang

          • Bullitt - 08, 09
          • GT - 05, 06, 07, 08, 09, 10
          • GT500 - 07, 08, 09, 10

              Related Mustang Categories