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Flowmaster American Thunder Cat-Back Exhaust (1998 Mustang GT, Cobra)

Item 18408
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      Video Review & Installation

      Hey I’m Justin with, and I’m checking out Flowmaster’s American Thunder Cat-Back exhaust, fitting the 98 Mustang GT, and Cobra. As you may know, Flowmaster offers a number of different mufflers, all with their own unique sound, in this case, the American Thunder for the 98 GT is built around my personal favorite Flowmaster offering, the super 44 two chambered muffler. There’s one muffler that really nails that iconic Flowmaster sound, this is it. This system is unique for a couple of different reasons: obviously for the use of those super 44 mufflers we just talked about, but also when it comes to the construction. The American Thunder uses 2.5” mandrel bent aluminized steel tubing, which may not be as good as stainless when it comes to resisting corrosion, but it’s definitely going to help keep the cost down versus that more expensive stainless steel. The tips are OE style 2.5” polished stainless steel, but as you can see that polished finish extends really far back, which is going to make for a nice clean finished look underneath the rear bumper. Because the exhaust hangers were designed differently on the 98, this exhaust will only fit the 98 GT and Cobra, unless of course you modify the hangers. Before getting started with the install, you will need to cut off your factory exhaust using a sawzall or something similar. Once you get that out of the way, getting the new Flowmaster bolted up should only take you about 2 hours from start to finish. Now let’s hear how the Flowmaster American Thunder catback sounds compared to our factory exhaust.

      Product Information

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


      • Aggressive Flowmaster Sound.
      • Super 44 Series Mufflers.
      • 2.5" Polished Stainless Steel Tips.
      • Mandrel-Bent Tubing.
      • Durable Aluminized Steel Construction.
      • Fits 1998 GT and SVT Cobra Mustangs.


      Flowmaster Sound.The Flowmaster American Thunder Cat-Back exhaust system with its mandrel bent tubing will improve your 1998 GT or Cobra Mustangs exhaust flow for an increase in power, and their included Super 44 Series Mufflers will improve your exhausts sound for a deeper throatier muscle car exhaust note.

      Quality Construction. Constructed from mandrel bent 2.5" 16 gauge aluminized steel tubing for it's corrosion resistant properties the Flowmaster American Thunder Cat-Back features Super 44 Series chambered mufflers with 2.5" diameter OEM style polished stainless steel tips for muscle car looks and sound.

      Fitment. This Flowmaster American Thunder Cat-Back exhaust system is designed to fit the 1998 GT or SVT Cobra Mustangs for both great looks and great sound.



      Flowmaster 17215

      CA Residents: WARNING: Cancer and Reproductive Harm -

      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (1) Right muffler assembly
      • (1) Left muffler assembly
      • (1) Right tailpipe assembly
      • (1) Left tailpipe assembly
      • (2) Clamps
      • (4) Lock Washers

      Tech Specs

      Cat-Back Exhaust Specifications
      Piping Material: Aluminized Steel Tip Material : Polished Stainless Steel
      Piping Size: 2.5" Tip Size: 2.5"
      Muffler Type: Chambered Fitment: 1998 GT or Cobra Mustangs

      Customer Reviews (100+)

        Questions & Answers

        10 More Questions

        Will It Fit My Mustang

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