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BBK Varitune Axle-Back Exhaust; Aluminized (11-14 GT)

Item 56240
AmericanMuscle no longer carries the BBK Varitune Axle-Back Exhaust; Aluminized (11-14 GT). Please check out Ford Mustang Axle-Back Exhaust for an updated selection.
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    Review & Installation Video

    Hey Justin with and I'm here with one of the most exciting new products to come along in sometime. I'm talking about BBK's Vari-tune fully tunable axle back exhaust system fitting all 2011 and newer Mustangs. Alright, before we start breaking down the Varitune this would be a great time to tell you to subscribe to our YouTube channel, just by clicking on the link below or on the AM logo up in the corner there. That's so you can stay up to date with the latest products, like these Varitunes, for your Mustang. Alright, getting into the Varitunes themselves, as the name suggests, this is a fully tunable muffler, so basically by adjusting this screw on the end of the muffler you can essentially change from a 3 chamber muffler to a single chamber muffler in a matter of minutes. Of course this gives you the best of both worlds by offering an exhaust that can be both loud or quiet depending on your mood. With the power valve fully closed like it is now, the exhaust tone will take on the characteristics of a 3 chambered muffler - it's going to be relatively soft and relatively quiet. But by opening the power valve all the way you are bypassing those first two chambers and it's at that point the muffler takes on the characteristics of a single chambered muffler. It's going to get a lot louder, and you're also going to get those rough around the edges sounds coming off the revs, all those pops and subtle backfires. Of course you can experiment with the valve being half open to see what kind of tone that will give you as well. So with the Varitones bolted up to our 14 GT, we were interested to see if they would make any power with the valves fully open as opposed to fully closed, well after a few Dyno pulls we actually put down about 8 more horsepower at the rear wheels with that power valve fully open. So now that you know what the Varitune does why would you want something like this? Well we as car people have the tendency to change our minds over time. So even though having the loudest exhaust possible when you first pick up your Mustang is the only way to roll for most Mustang owners out there, over the years you might change your mind a little bit, and you'll probably want to tone it down a little bit. That's where the Varitune comes into play. The Varitune gives you the luxury of having a loud and a tame muffler in one package and allows you to change your tone easily as your preferences change. Getting into the actual construction of the Varitune, BBK offers this exhaust in aluminized steel and full-stainless, with a slight difference in price between the two. In addition we're looking at 3" mandrel bent tubing, and these brightly polished 4" tips, with an optional black tip available from the drop down menu just in case you wanted to switch up the look a little bit. If you're not watching this on our site already, go ahead and click the link below to head back to our site to see a wide variety of BBK products available for your Mustang. Installing the Varitune is just like installing any other axle back for your Mustang and can easily be done in about an hour using basic hand tools. Adjusting your sound is even easier and only requires a 7/16th wrench and socket and a minute or two of your time. Now if you should run into any problems you can always call our customer service reps at 1-855-422-7439 or feel free to shoot them an email at Now let's hear how the Varitune sounds on our 2014 with the valve fully closed first, and then fully open.

    Product Information

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


    • BBK Varitune Axle-Back with "Adjustable Power Valve"
    • Change from a Three to One Chamber Exhaust for More Power and Sound
    • 8-10 Decibel Range Difference
    • Aluminized Steel Construction
    • 4" Polished 304 Stainless Steel Tips
    • Direct Bolt-On, No Cutting or Welding Required
    • Fits 2011-2014 GT Mustangs


    Adjustable Sound. This BBK Mustang Axle-Back Exhaust system features BBK's patented tunable Varitune performance mufflers that allow you to change from a mellow three chamber exhaust sound to a rich throaty straight-through exhaust note with just a twist of a wrench, for a 8 to 10 decibel sound level difference!

    How It Works. BBK Varitune performance mufflers utilize an internal "Adjustable Power Valve." When in the closed position the valve blocks the exhaust flow, forcing it through all three chambers of the muffler for a classic mellow sound. When in the open position, the valve "uncorks" the exhaust flow, allowing it to take the path of least resistance, acting more like a straight-through muffler for a rich throaty exhaust note. This unique design is perfect for personalizing the power and sound levels of your Mustang to suit your own specific needs.

    Aluminized Steel Construction.
    Constructed from highest quality Aluminized Steel available, this BBK Performance Axle-Back exhaust system features Varitune chambered mufflers that end with 4" polished 304 stainless tips for impressive looks and sound. The tips exit in the stock locations so no modifications are required to the rear bumper cover.

    Application. This BBK Varitune Axle-Back Exhaust is designed as a direct fit bolt-on upgrade for the 2011-2014 GT Mustangs equipped with the 5.0L 32V DOHC V8 coyote Engine.

    Fitment: Details

    CA Residents: WARNING: Cancer and Reproductive Harm -


    Customer Reviews (12)

    Write a Review

    Ratings Summary

    4.3 out of 5 overall rating from 12 customers

    Installation Time: Afternoon

    Installation Cost: 0-$100

    • December 18, 2019

      5 2014 GT - Freacky Installation Time: Less than 1 Hour

      Helpful (0)
    • March 17, 2018

      3 2012 GT - michael Installation Time: Less than 1 Hour

      Love the sound from outside...

      The car sounds great from outside with full bbk setup from headers back but the drone is horrible.

      Helpful (7)
    • January 24, 2018

      4 2014 GT - Jake Installation Time: Afternoon

      Great for old ma

      Its great if you want it loud or you head out on a trip with the wife you can turn the volume down

      Helpful (6)
    • July 23, 2017

      5 2014 GT - RandallL Installation Time: Less than 1 Hour

      A very nice soud

      With the valve closed a bit louder than stock. open them up and you can feel the power

      Helpful (6)
    • July 06, 2016

      2 2014 GT - WHITECOYOTE

      Sounds broken

      I have off road H with cat deletes and the BBK varitune. The build quality is ok, but should be better. The exhaust keeps moving, bellow 3K RPM it just sounds like air moving through the muffler. Yet it still has drone. above 3K it sounds like a WRX, not in a good way. When it's closed it should be quieter, when it's open it should be louder. Overall not happy.

      Helpful (7)
    • November 28, 2014

      5 2014 GT - TheMachine Installation Time: Less than 1 Hour

      Amazing Sounds and Power

      Better than advertised. I did a ton of research on several other muffler upgrades and chose this one based on the description and videos I watched. One of the advantages to this system is the ability to turn the volume up or down just by screwing the baffle in or out. I am not really mechanical, so I had them installed by my local dealer and it took no more than 30-45 minutes. As the name says, "varitune", the exhaust note is perfect with a great balance of low end grunt, and a high pitched scream when you get up in the rpms. I have gotten a ton of complements on them and they turn lots of heads as I go through the gears down the street. When the baffle is fully open, I experience an increase in power and sound along with a tremendous amount of pops and backfires when decelerating which was mentioned in the video. Great job BBK!!!

      Helpful (8)
    • July 18, 2014

      5 2014 GT - Ferg131 Installation Time: Less than 1 Hour

      Awesome Axleback system

      This is a great product if you aren't sure which system to get. The sound is perfect, it's not obnoxious at higher rpms. It's not the best fit but it only took about an hour to put on. It's not exactly how I expected it to sound but it grew on me. I highly recommend this system.

      Helpful (6)
    • July 04, 2014

      5 2011 GT - Txfishermn Installation Time: Afternoon

      Pretty Cool!

      I chose these mufflers simply because you can control how much baffle you want. We use our Stang to travel in and the wife isn't thrilled with loud. A crescent wrench and 7/16 wrench changes it quick! It's throaty and loud when wide open but discreet baffled. My throttle response is much better as well. None of the drone or rasp that I've heard with other mufflers. I haven't changed anything else on the car yet and I'm very glad this was my first choice! I'm hoping it'll wake the neighbors after headers, X pipe and mid pipes! While still simply adjusting two bolts to quiet it down when needed!

      Helpful (7)
    • June 25, 2014

      5 2014 GT - Wallo Installation Time: Less than 1 Hour

      rumble young man rumble!

      The varitune axle back on my mustang gt is like heaven on earth. Starting up my mustang and hearing the rumble of this muffler just puts a smile on my face every time. This product will definitely add the after market "grow" that will turn heads. Its also very easy to install.

      Helpful (6)
    • April 29, 2014

      5 2014 GT - RealEstateDean Installation Time: Shop Install Installation Cost: 0-$100

      Sounds great

      Just what I was looking for.I wanted to be able to adjust the sound in case it was too loud.For now I have it wide open,sounds great when excelerating and I get some nice popping when you get off the gas.If I ever want to tone it down just turn the bolt.

      Helpful (7)

    Questions & Answers (1 answers)

    1 Top Rated Question

    life expectancy of this vs the stainless steel via rust/corrosion? Trying to decide between the BBK Varitune exhaust, aluminized vs stainless for longevity. How durable are they, comparably?

    • The aluminum steel exhaust has been on my 1996 F250 since day one. It shows some rust but still solid as a rock. I chose the aluminized steel over stainless for this reason. Will you honestly keep your Stang for life? Will you see the stainless mufflers? I said no to these questions and saved myself $100 to spend on something else.

    Helpful (0) Show 2 more answers
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    Installation & What's in the Box

    Installation Info

    What's in the Box

    • (1) Passenger side muffler assembly
    • (1) Driver side muffler assembly

    Tech Specs

    Will It Fit My Mustang

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