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Flowmaster American Thunder Cat-Back Dual Dump Exhaust; Stainless Steel (86-98 Mustang GT, Cobra)

Item 18431
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      Video Review & Installation

      Hey, Justin here with, breaking down Flowmaster’s American Thunder Cat-Back Dual Dump exhaust fitting the 86-98 GT and Cobra. Obviously the big difference between this system and other exhausts is the way it exits, as you can see there are no real tail pipes. Instead, everything flows with these super 44 series mufflers, through the turn downs and then dumps right out underneath the car right in front of the rear axle. So why would you want to do this? Well, some would say it gives the rear of the car a different, some might even say cleaner look by deleting those tail pipes altogether, there’s no real difference in performance to speak of, although it might be slightly louder inside the cabin versus your standard tail pipe. As for the system itself, we’re looking at a full 409 grade stainless steel construction throughout, and what little piping there is has all been mandrel bent. That iconic Flowmaster sound comes courtesy of Flowmaster’s twin super 44 series mufflers which Flowmaster claims is one of the most aggressive mufflers they offer in terms of overall sound. Because Ford chose to weld the factory exhaust on the Fox bodies and the SN95’s, you will need to cut it off with a sawzall or something similar before getting started with the install. Once you get that out of the way, getting the new Flowmaster bolted up is a pretty straightforward task that should only take you about 2 hours from start to finish. Now let’s hear how Flowmaster’s dual dump American Thunder sounds compared to our factory exhaust.

      Product Information

      Features, Description, Reviews, Q&A, Specs & Installation


      • Aggressive Flowmaster Sound
      • Dual Dump Exhaust
      • Super 44 Series Mufflers
      • Mandrel-Bent Tubing
      • 409 Stainless Steel Construction
      • Fits 1986-1998 GT and Cobra Mustangs


      Flowmaster Sound. The Flowmaster American Thunder Cat-Back Dual Dump exhaust system with its mandrel bent tubing will improve your Mustangs exhaust flow for an increase in power, and the included Super 44 Series Mufflers will give your Pony a deep throaty muscle car exhaust sound.

      Dual Dump Exit. This Flowmaster American Thunder Cat-Back system features a Dual Dump design that exits the exhaust in front of the rear wheels for a stealthy appearance.

      Stainless Steel Construction. Constructed from mandrel bent 2.5" diameter 16 gauge stainless steel tubing for it's corrosion resistant properties the Flowmaster American Thunder catback features Super 44 Series chambered mufflers for that classic muscle car sound.

      Application. This Flowmaster American Thunder Stainless Steel Cat-Back Dual Dump exhaust system is specifically designed to fit the 1986 to 1998 5.0 LX, GT and SVT Cobra Mustangs.



      Flowmaster 817574

      CA Residents: WARNING: Cancer and Reproductive Harm -

      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (1) Left muffler assembly
      • (1) Right muffler assembly
      • (2) Turn down pipes
      • (2) Clamps
      • (2) Hanger keepers

      Tech Specs

      Cat-Back Exhaust Specifications
      Piping Material: 409 Stainless Steel Tip Material : N/A
      Piping Size: 2.5" Tip Size: N/A
      Muffler Type: Chambered Fitment: 1986-98 GT and SVT Cobra Mustangs

      Customer Reviews (100+)

        Questions & Answers

        10 More Questions

        Will It Fit My Mustang

        • Cobra - 93, 94, 95, 96, 97, 98
        • Cobra R - 93, 95
        • GT - 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98
        • LX - 87, 88, 89, 90, 91, 92, 93
        • Other - 86

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