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Flowmaster American Thunder Cat-Back Exhaust (11-12 GT)

6 Reviews
Our Price

$823.64

  • Item #18428
  • MPN# 817500

  • Market Price $914.99
  • You Save 10% ($91.35)
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Product Videos Customer Photos
Features
  • Aggressive Flowmaster 60-Series Delta Flow Sound
  • Durable 409 Stainless Steel Construction
  • 3" Mandrel-Bent Tubing
  • 4" Polished Stainless Steel Tips
  • Includes Two Flowmaster 60 Series Mufflers
  • Fits 2011-2012 GT
Description
Signature Flowmaster Sound. Give your coyote Mustang that unmistakeable 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 Mustangs exhaust flow for an increase in power, and the included 60 Series Delta Flow Mufflers will improve your exhausts sound for a deep aggressive muscle car exhaust note.

Reuses Stock Cats. The included Flowmaster Scavenger X-Pipe bolts up directly behind the factory catalytic converters with no cutting required saving you time and money. By reusing your stock catalytic converters, you ensure that your Mustang is smog-legal.

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 impressive muscle car looks and sound. As an added bonus the tips are embossed with the "Flowmaster" logo for true custom styling.

Application. This Flowmaster American Thunder Cat-Back exhaust system is designed to fit the 2011 to 2012 5.0L coyote Powered GT Mustangs equipped with either aftermarket shorty headers or the factory manifolds. Does not fit Shelby GT500 models.

Fitment: 2011 2012 Details

What's in the Box
  • (2) Muffler Assemblies
  • (2) Over Axle Pipes
  • (4) Clamps
Installation Info
Tech Specs
Axle-Back Exhaust Specifications
Piping Material: 409 Stainless Steel Tip Material : Polished Stainless Steel
Piping Size: 3.0" Tip Size: 4.0"
Muffler Type: Chambered Fitment: 2011-2012 GT
Will it fit my Mustang?
  • Boss 302 - 12
  • GT - 11, 12

Designed to be used with the factory manifolds or aftermarket shorty headers installed.

Most Helpful Reviews

4/5
Flowmaster sound!

I researched extensively before I decided to buy this exhaust. I wanted something with the right sound, but I didn't want the rattle the neighbors windows. We did the install in my garage and had to cut ...

Read More
Helpful (2)

4/5
Let me save you some time and frustration...

First of all, this exhaust system is the definition of classic Muscle Car sound. I was very happy with the deep sound, just enough of burble and almost zero drone. BTW, the video and sound clips out there ...

Read More
Helpful (2)

Overall Rating 4.3 out of 5 stars
Read All 6 Reviews

Review & Install Video

Hey I’m Justin with AmericanMuscle.com, and I have with me FlowMaster’s American Thunder series Cat-back exhaust fitting all 2011 and newer Mustang GTs. The thunder you get from using this system comes from Flowmaster’s 60 series delta flow mufflers, which will still give you that classic muscle car sound, but will still be a bit milder than Flowmaster’s Outlaw series, or their Force 2 exhaust, which utilizes a more aggressive 40 series muffler. The American Thunder is a true cat back exhaust, meaning it eliminates your factory H-pipe utilizing 3” mandrel bent tubing all the way up to your factory cats. One thing we noticed with our mid pipe is it features a mini crossover, just to equalize your exhaust flow. Everything exits out these 60 series delta mufflers, and out these dual 4” hand polished tips. Getting the American Thunder bolted onto your ride is a straight forward affair which should take you no more than 2 hours using standard hand tools. Now let’s hear how Flowmaster’s American Thunder sounds compared to our factory exhaust.

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Customer Reviews (6) Write a Review

Overall Rating 4.3

out of 5 stars

Installation Time:Afternoon

  • Loudness / Volume 4.666667 4.7
  • Exhaust Note 4.833333 4.8
  • Fit & Finish 4.166667 4.2
  • Bang For Your Buck 4.333333 4.3



  • 4/5

    Installation Time: Afternoon

    January 06, 2014

    Let me save you some time and frustration...

    First of all, this exhaust system is the definition of classic Muscle Car sound. I was very happy with the deep sound, just enough of burble and almost zero drone. BTW, the video and sound clips out there on the web do not do this exhaust justice, hear one in person and you will be sold... For those of you buying this product, here is a tip for you that is worth at least a few beers, as this will save you a lot of time and frustration: GET YOURSELF A SET OF CORRECTLY SIZED CLAMPS before you start the job!!! The clamps that come with the set are wwwaaaayyyyy undersized, I can't believe Flowmaster ships them with this exhaust!!! It is IMPOSSIBLE to put them on, they are just too small. It only took me 3 hours to put the exhaust in and have everything aligned, but then I wasted another 2 hours fighting with the clamps. After a few curse words and a couple of wrenches thrown across the garage I gave up. I ordered a set of 3" clamps from another vendor. I had to wait three days to finish the job and get my car back on the road bc of stupid clamps! Once I got the new clamps though, everything went perfectly smooth. I almost forgave Flowmaster for the clamps after I heard the car come alive when I turned the key :)

    Konrad

    Year: 2011 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 3 New Jersey, USA

    Helpful (2) (0)

  • 4/5

    Installation Time: Afternoon

    July 09, 2013

    Flowmaster sound!

    I researched extensively before I decided to buy this exhaust. I wanted something with the right sound, but I didn't want the rattle the neighbors windows. We did the install in my garage and had to cut the old exhaust pipe in half to get it over the rear axle. It took significantly more than the 2 hours estimated, but most of that was cutting the old pipes. Pros: This exhaust has great sound when you want it and is not too noisy when you don't want it. At idle and when cruising it has a nice low rumble that is unmistakable and when you step on the gas, it roars to life and turns heads. This is how the car is supposed to sound! Besides the fit items listed below, everything else went together perfectly. Cons: The clamps that come with the pipes seem to be undersized and it was very hard to get them on. The passenger side tip is not centered and I can't get it to center - I plan to take it to a shop to see what they can do. A minor point, but the instructions have you remove the muffler mounts at the very end of the removal steps, but I had to remove the driver's side mount in order to get the muffler off.

    paul88

    Year: 2012 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 3 San Antonio, Texas

    Helpful (2) (0)

  • 5/5

    Installation Time: Afternoon

    September 25, 2015

    American thunder cat back

    Great exhaust system! Took about 2 hours of actual labor with the uninstall of the stock system and install of this system! Night and day difference over stock. Love the growl with the cold starts in the morning! Interior sounds great not real quiet but not to loud, definitely road trip-able! Loyd and aggressive if your outside the car! Definitely recommend!

    krazy

    Year: 2011 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 5 henderson, NV

    Helpful (1) (0)

  • 5/5

    Installation Time: Afternoon

    May 01, 2012

    Great sound

    This is my second mustang, and second time I purchased a catback by Flowmaster. I was pleased with the quality of the first one (on a 2000 mustang v6) and I am extremely pleased with the sound on my '11 GT. The exhaust sounds great from outside, and is not deafening to those in the car. A perfect addition to anyone looking for a more meaty sound from their mustang, without it being overwhelmingly loud. A++

    Ftolimited

    Year: 2011 Model: GT Driving Style: Street / Strip 'Stangs I have owned: 2 Bridgewater, NJ

    Helpful (1) (0)

  • 4/5

    Installation Time: Afternoon

    April 28, 2012

    exhaust

    fits nice, looks good, gives the car the sound it should have

    dle0962

    Year: 2011 Model: GT Driving Style: Daily Driver 'Stangs I have owned: 3 stroudsburg pa

    Helpful (1) (0)

  • 4/5

    Installation Time: Less than 1 Hour

    January 29, 2012

    Who needs a radio with this sound!?

    The new exhaust has a great sound and given my GT a true muscle car note. While it is a loud exhaust, its not an "annoying loud" which forces fellow drivers to have to turn up their radios. Rather, it is a loud that grabs the attention of anyone who appreciates a good, true american, muscle car! There is a noticeable increase in horsepower at lower rpm's, and higher highway gas mileage as well. Some drone has occurred in between 1500-200 rpm, but it's intermittent and mild so far. I would recommend this product to all mustang lovers.

    Mike1988

    Year: 2011 Model: GT Driving Style: Daily Driver Tucson, AZ

    Helpful (1) (0)

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