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Flowmaster American Thunder Cat-Back Exhaust w/ X-Pipe (13-14 GT)

Market Price $915.27 You Save 12% ($105.30)

$809.97

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  • Item 18446
  • MPN# 817587

In Stock Ships same business day. Choose options to add to cart

Features, Video & Details

  • 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 2013-2014 GT

Review & Installation Video

Review & Install Video

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.

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.

Reuses Stock Cats. The included Flowmaster Scavenger X-Pipe bolts up directly behind the stock 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 2013-2014 5.0L coyote Powered GT Mustang equipped with either aftermarket shorty headers or the stock manifolds. Does not fit Shelby GT500 models.

Fitment: 2013 2014 Details

What's in the Box
  • (1) Right muffler assembly
  • (1) Left muffler assembly
  • (1) Scavenger X pipe assembly
  • (1) Right intermediate pipe
  • (1) Left intermediate pipe
  • (4) Band clamps
  • (2) Hanger keepers
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: 2013-2014 GT
Will it fit my Mustang?
  • Boss 302 - 13
  • GT - 13, 14

Most Helpful Reviews

5/5
Awesome

Install was quick and easy, perfect sound, a small amount of drone but not enough to bother you, still makes me smile when I get on it

Helpful (1)

5/5
Best value out there

I wanted something that would free up my exhaust without being too loud. I am completely happy with this system. I added the Bama 91 race tune and cut my 1/8th mile race time by .4 seconds. Better than ...

Read More
Helpful (1)

Overall Rating 4.8 out of 5 stars
Read All 21 Reviews

Customer Photos (3) Submit Your Photo

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4 Questions / 4 Answers

Ask a Question

Would this exhaust go well with some long tube headers without a problem such as the bbk or pypes longtubes?

Richeh

  • As long as the long tube headers had the ball socket connection on the end. If not you would probably have to get an exhaust shop to install them

    fast5ohh

    Good Answer (0) (0)

Answer This Question I need this answered (0) (0)

Cause check engine light? Will this system cause the "Check engine" light to come on?

uttersqueez

  • No it will not cause a check engine light. It does not remove the catylitic converters

    fast5ohh

    Good Answer (2) (0)

Answer This Question I need this answered (0) (0)

does this only fit on stock or can i get short tube headers and this to bolt on after? i want to get shorty ceramic headers, and an exhaust system all the way back for better flow. will that work?

Mike12

  • Absolutely! Ceramic Shorty Headers would be a great complement to the American Thunder Catback. Hope this helps!

    LisaS

    Good Answer (0) (0)

Show 1 more answer Question Resolved

Will this fit my 2012 GT? This (http://www.americanmuscle.com/flowmaster-american-catback-1112gt.html) us the 2012 gt model, but it isn't in stock and looks virtually identical to the 2013 version.. is there a real difference?

ChuckSkyline

Answer This Question I need this answered (0) (0)

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Customer Reviews (21) Write a Review

Overall Rating 4.8

out of 5 stars

Installation Time:Full Day

Installation Cost:$100-$250

  • Loudness / Volume 4.619048 4.6
  • Exhaust Note 4.809524 4.8
  • Fit & Finish 4.333333 4.3
  • Bang For Your Buck 4.523809 4.5



  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    June 07, 2016

    Best value out there

    I wanted something that would free up my exhaust without being too loud. I am completely happy with this system. I added the Bama 91 race tune and cut my 1/8th mile race time by .4 seconds. Better than I expected!

    DGC

    Year: 2013 Submodel: GT

    Helpful (1) (0)

  • 5/5

    Installation Time: Less than 1 Hour

    May 29, 2015

    Awesome

    Install was quick and easy, perfect sound, a small amount of drone but not enough to bother you, still makes me smile when I get on it

    Geif

    Year: 2014 Submodel: GT Houston, Tx

    Helpful (1) (0)

  • 5/5

    Installation Time: Less than 1 Hour

    May 06, 2014

    Great sounding exhaust!! It's what a mustang should sound like! !

    I was ify about buying this item because of the bag fitment reviews it received. I thought to myself for the price I'll deal with it. Turns out it went right in with no issues what do ever. I can only imaging those customers did not wait to the end to tighten everything. Great item. I love the exhaust note it has! It's what a 5.0 should sound like! Performance wise I didn't notice any gains but a catback is mainly for sound and not power. I'm all stock except for the catback.

    SlowGrabberBlue

    Year: 2014 Submodel: GT Phoenix, AZ, USA

    Helpful (2) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    March 22, 2013

    Loud, but not too loud.

    Mustang GTs have always turned my head for the way they sound. I thought after buying a 2013 that the last thing I'd do was put an exhaust system on it. Well, that was the second thing I did to it after a C.A.I. and am I glad I did. Not only does it sound better, but I can notice the difference in acceleration. I'm quite glad I didn't get the Outlaw, for it might be too loud. My neighbor said he wasn't hearing me start my Mustang (he has a SS Camero) and was wondering if I drove it at all. He hasn't asked that after the Flowmaster American Thunder was installed.

    Roysun

    Year: 2013 Submodel: GT Salisbury, NC, USA

    Helpful (2) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    May 19, 2014

    WOW!!!

    I have always used Flowmaster products on all my vehicles-from Corvettes to pickups!! They have always sounded good and improved performance! But, on my 13 GT it has outdone itself to the max!! It has a low rumble at idle,a great roar on full throttle accel and a nice tone at cruising speeds up to 80 mph!! Best investment I have ever made!! And at steadt hiway speeds has increased my gas mileage to boot!! LOL good deal all the way around!!!

    horsearound

    Year: 2013 Submodel: GT Raeford, NC 28376, USA

    Helpful (1) (0)

  • 5/5

    Installation Time: Afternoon

    July 01, 2013

    Best 5.0 exhaust!

    When I first installed this system on my car there was a major fitment issue. I called AM and they sent me a brand new kit! After installing the second system it was perfect. The sound alone makes this exhaust worth the problems. The stainless steel is average quality but none of that matters when you hear the sound it makes! Its not a quiet exhaust but its very pleasant and mellow at low RPM. I would recommend this exhaust over any other system. I'm not sure about power gains as I installed this with a CAI and tune.

    GTEd2013

    Year: 2013 Submodel: GT

    Helpful (1) (0)

  • 5/5

    Installation Time: Less than 1 Hour

    May 14, 2013

    Love the sound

    Sounds a lot louder than my friends magnaflow cat back . But his goes from the h pipe. Glad I didn't waste my money on that exhaust . Also like the little extra power.

    goodfun

    Year: 2013 Submodel: GT nj

    Helpful (1) (0)

  • 3/5

    Installation Time: Afternoon

    May 08, 2013

    Not all that impressed but not to bad.

    The scavenger pipe was well made with excellent welds. The fit was off connecting to the existing cats but it was mentioned in the manual and was easily adjusted. Measure and dry fit prior to installation. It was noticed that if you are not installing this system on a lift the old over axle mid pipes will not come out without at least 24” of ground clearance. Be aware and use a saw or angle grinder to cut them as close to the rear axle as possible. The fit is tight and exact but the hangers on the mufflers are not welded very well and had to be removed and re-welded in order for proper fit. Some quality issues on mufflers with paint. In order to get the mufflers mounted in the hangers, the forward hanger on the drivers side had to be removed then reinstalled with the muffler in it and the passenger side mid pipe had to be moved forward. Minor issues in all.

    Duke5

    Year: 2013 Submodel: Other Texas

    Helpful (1) (0)

  • 4/5

    Installation Time: Afternoon

    June 07, 2015

    American Thunder Cat Back

    American Muscle shipped fast and arrived in good condition even though the box had little packing material in it. I did this install on a few days ago, started at 430 and didn't finish till 10 pm, taking off the factory exhaust is not easy but that was just the beginning. We put the car high in the air with 4 jack stands and we still had clearance issues getting the flowmaster mid pipes over the axles. I don't recommend trying to install this exhaust unless you have a lift for clearance reasons. Due to the fact that we couldn't get mid pipes over the axle we had to drop the whole rear end to have enough room to complete the exhaust. Once on ,everything fit really well with no more issues. This was a difficult install but it was worth it, the tone of this system is fantastic, slightly louder then stock at idle but even a touch of the gas pedal let's loose this great deep tone flowmaster is known for. As well there is no irritating drone at high way speeds. I recommend this system 100

    Matt

    Year: 2013 Submodel: GT Tampa FL

    Helpful (0) (1)

  • 5/5

    Installation Time: Afternoon

    September 18, 2013

    Great sound with the stock headers and cats!

    Excellent product and this is the first exhaust system that I have purchased for the new 5.0s. I have bought Flowmaster in the past and I was satisfied with the sound and installation.

    Paul74

    Year: 2014 Submodel: GT Cape Coral, FL, USA

    Helpful (0) (1)

  • 5/5

    Installation Time: Afternoon

    July 24, 2013

    Sound Awesome!

    The exhaust sounds very nice cruising around and is not overly loud. The fitment was slight off. After installing the exhaust myself and spending hours trying to get it to line up I gave up and took it to an exhaust shop. They took it off and the left side (drive side) pipe was about an 1" off on the bend. They re-bent it and installed it. Now its perfect. Love the sound, but after paying a shop to fix the bend I could have gotten the Borla's. I do recommed this product and imagine it was a 1 in million product defect. I have numerous other Flowmasters and they have been perfect.

    lwevert

    Year: 2014 Submodel: GT Honolulu, HI

    Helpful (0) (1)

  • 5/5

    Installation Time: Full Day

    October 05, 2016

    How the 5.0 was meant to sound!

    The American Thunder Exhaust makes the 5.0 sound like it should have from the factory! It's phenomenal. I was looking to give my car that muscle car rumble-a modern version of the sound of my '60s Mustangs, and this did it! My only complaints with the product are: 1) It requires you to reuse two of the factory clamps off of the factory exhaust. I really hated cutting those off of the original exhaust as I wanted maintain it's originality. I'm not sure why Flowmaster couldn't include them. I could not find any suitable aftermarket ones either. 2) My second issue was how difficult it was to adjust the exhaust tips. We spent about two hours trying to get them straight and away from the rear valance. One of the tips still ended up so close to the lip that it vibrated over and rubbed the paint off. I had to get it professionally straightened and the paint fixed. Probably could have been avoided if I had more experience installing exhaust systems, but if you also don't have any previous experience you may want to consider this. The results were exactly what I was trying to achieve though, the car sounds incredible. The very first day I was driving it after the installation, a guy pulled up next to me in a 1966 Corvette and made it a point to roll down his window and tell me how incredible my car sounds! Not the most likely guy to give a Modern Mustang a compliment, so this sound has broad appeal. I highly recommend this product, it's a great value, and it delivers. Just install with care.

    TH

    Year: 2014 Submodel: GT

    Helpful (0) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    October 01, 2016

    The Perfect Balance

    This is the perfect exhaust for those who want to hear their motor, but not be the annoying guy with obnoxiously loud car. At idle, it's louder than stock, but only slightly and with a deeper tone. Around 2.5-3k rpm, watch out. That's where you hear it- pure music. And it only improves as you go up in the powerband. My only regret is why I didn't put this system on years ago. One word of caution though: the kit fit well, but the tips where not aligned and symmetical. I had the shop that did the install cut the tips off and re-weld them to make them symmetrical. The end results is perfect. In the end, it's totally worth it.

    Tony

    Year: 2014 Submodel: GT

    Helpful (0) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $250-$500

    May 06, 2016

    Sounds so good and you feel the difference.

    I got 2014 GT with cold Intake and tuner wanted to get exhaust ordered this one and when I started it sounded insane. Totally new sounding vehicle. Straight muscle car sound. No drone. Sounds so beautiful. Other them forgetting to send clamps I'm very happy. This what mustang should sounds like.

    Beast

    Year: 2014 Submodel: GT

    Helpful (0) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    July 20, 2015

    The boy sounds like he"s become a man

    This exhaust is a grade above the stock equipment. Love the roar it creates especially on cold starts and I can't help punching it. Gives me what I felt a Mudtang should sound like.

    Bushmaster

    Year: 2013 Port Reading, NJ

    Helpful (0) (0)

  • 5/5

    Installation Time: Afternoon

    December 18, 2014

    Nice deep tone

    Perfect fit. Easy to install. Noticable improved throttle response gave my 13 gt the classic "flowmaster" sound. Not raspy at all

    fast5ohh

    Year: 2013 Submodel: GT Logan, WV 25601, USA

    Helpful (0) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: 0-$100

    October 18, 2014

    Cat back exhaust

    This is absolutely 1 of the best things (of many) done to this car. I am able to hear the engine at start up, has a great sound when you get on it, a nice burble when you downshift and no drone. Nothing but compliments from people that have heard it!!!

    rod14

    Year: 2014 Submodel: GT Las Vegas, NV, USA

    Helpful (0) (0)

  • 5/5

    Installation Time: Afternoon

    September 24, 2014

    Gorql in the daily grind

    Its really opens up the sound and gives the car that signature growl that I have come to love on a GT... all while not being to loud for my 30 minute daily commute.

    GCochran

    Year: 2014 Submodel: GT GA

    Helpful (0) (0)

  • 5/5

    Installation Time: Less than 1 Hour

    September 01, 2014

    American Thunder exhaust system review

    I had this system installed by a shop. It took the shop 1/2 hr. to install, no mention of problems. Cost was $150 plus tax. On start up it is fairly loud but at normal idle it's close to the stock sound level. Easy take off and cruising is also close to the stock system. Once you step down on the gas some the sound level goes up, the more you step on it the louder it gets. This system can easily be used on a daily driver, or when taking a long trip. Very nice set up, great value for the money you will not be dissapointed.

    Ken2

    Year: 2013 Submodel: GT Cedar Rapids, IA, USA

    Helpful (0) (0)

  • 4/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    August 26, 2013

    Sounds Great, but a hassle install.

    I had a shop install this exhaust and i was quoted $65 to $150. i ended up paying the full 150$. I was quoted 2 hours, i got the car back 5 hours later with them stating that the hangars were bent and would allow the exhaust to sit properly and i wanted a better fit than what i had i would have to contact Flowmaster. I contacted American Muscle for warranty assistance but i was told to contact Flowmaster directly I contacted Flowmaster and the rep there had me get a second opinion from one of there authorized dealers. I went and had them adjust the pipes. they ended up cutting one of the tips off and re-welded it, apparently it was welded on at an angle.. Flowmaster was great and offered a full replacement in the event i was not happy with the fix. The sound is great, The fit is okay, i would have like it to fit right the first time with no modification, one tip sets about 3/4" farther out than the other. I purchased this mainly because flowmaster offered at $100 rebate at the time of purchase.

    LVSGMS197

    Year: 2014 Submodel: GT Las Vegas, NV, USA

    Helpful (0) (0)

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