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BBK Varitune Axle-Back Exhaust - Aluminized (05-10 GT)

Market Price $509.99 You Save 12% ($60.00)
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  • Item 56238

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    Features, Video & Details

    • AmericanMuscle Exclusive
    • 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 2005-2010 GT and Bullitt Mustangs

    Review & Installation Video

    Review & Install Video

    Hey I’m Justin with, here with quite possibly one of the most exciting new products to come along in some time, I’m talking about BBK’s Varitune fully tunable axleback exhaust system, fitting the 2005-2010 Mustang GT. If you haven’t checked out BBK’s complete lineup available for your Mustang, just click the link below to head back to our site, and see for yourself. Let’s break these mufflers down a little further, the Varitune as the name suggests is a fully tunable muffler, allowing you to adjust not only the sound but also the performance. How does it all work? Well, BBK was kind enough to send along the internals of one of these mufflers, to show you how it all goes down. By adjusting this screw on the outside of the muffler, you can change from a 3 chambered muffler to a single chambered muffler in a matter of minutes. With the power valve closed like it is now we are essentially running a 3 chambered muffler, which is going to keep the sound levels down considerably. By turning this screw and opening the power valve complete, you are transforming that 3 chambered muffler into a single chambered muffler, allowing the exhaust gasses to bypass those first two chambers complete, before being dumped in the third chamber and exiting out the tip here. During our actual testing, not only did I notice the tone to be slightly louder with the valve open, but it also took on a more aggressive tone. What I mean by that is it had the tendency to grumble and pop a little bit more coming down off the revs. BBK does offer an aluminized steel version, in addition to a full stainless version of the Varitune, with a slight difference in price between the two. In addition to that the kit does feature 3” mandrel bent tubing, in addition to these 4” brightly polished tips. There are 4” black tips available from a dropdown menu, if you’d just like to switch up the look a little bit. Installing the Varitune is just like installing any other axle back exhaust, it can easily be done in about an hour’s time using basic hand tools. Adjusting that sound tube is even easier and can be done using a wrench in about a minute of your time. If you have any questions about the install, or about the Varitunes in general, get in touch with one of our customer service reps, you can email them at, or give them a call at 855-422-7439, and if you haven’t done so already, go ahead and subscribe to our YouTube channel by clicking the link below, or up in the corner. We have hundreds of exhaust sound clips that you can hear, that might help you with your purchase. Now let’s hear how the Varitune sounds on our GT with the valve fully closed and fully open.

    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 2005-2010 GT and Bullitt Mustangs equipped with the 4.6L 24V SOHC Modular V8 Engine.

    Fitment: 2005 2006 2007 2008 2009 2010 Details

    MPN# 4100

    CA Residents: WARNING: Cancer and Reproductive Harm -

    What's in the Box
    • (1) Passenger side muffler assembly
    • (1) Driver side muffler assembly
    Installation Info
    Tech Specs
    Will it fit my Mustang?

      Customer Photos (2) Submit Your Photo

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        Questions & Answers (3)

        3 Top Rated Questions

        Does this exhaust drone on the highway at all? I need a good exhaust system but do not want to deal with the drone that comes with some flowmaster or pypes systems. (I will usually keep the exhaust set to one valve most of the time).

        • The BBK Varitune Axle-Back Exhaust - Aluminized (05-10 GT) will have some drone to them. The only two companies we offer that gaurentee no drone will be Corsa and Roush exhausts systems.

        Helpful (1)

        are they street legal in new york state in 3 chamber adjustment ?

        • This would be difficult to answer as sound ordinances differ from county to county within each state, so we would not be able to confirm this information for this BBK Varitune Axle-Back Exhaust. We would highly recommend speaking with your local municipality.

        Helpful (0)

        Do I need different tunes? Would I need separate tunes for open and closed?

        • As in do you need to retune the engine? No, mufflers don't have that much of an impact on the cars electronics.

        Helpful (0) Show 1 more answer
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          Customer Reviews (5) Write a Review

          Overall Rating 5

          out of 5 stars

          Installation Time:Afternoon

          • Loudness / Volume 4.75 4.8
          • Exhaust Note 5 5
          • Fit & Finish 4.75 4.8
          • Bang For Your Buck 4.75 4.8

          • 5/5

            Installation Time: Less than 1 Hour

            July 16, 2018

            A mod that is really custom

            An easy installation that looks and sounds great. I purchased the BBK's to replace the stock GT mufflers on my V6 and I am very pleased. At first, I ran the mufflers full open and that produced too much drone for my taste when highway driving. I partially closed the power valves to get that low rumble/drone sound that I like to hear. The 4 inch exhaust tip really fills out the hole I needed to cut on the driver's side when I modified my V6 to dual exhaust from a loaner GT I found in the junkyard. I like the look so much that I doubt if I am going to install the dual exhaust rear valance. To have three types of muffler loudness in one unit (Low/Med/Loud) that you can tailor to your individual preference is well worth the money.


            Year: 2005 Submodel: GT

            Helpful (11)

          • 5/5

            July 20, 2016

            Two for the price of one

            Love these, researched many and bbk did excellent job in n the design of these. You have two different sounding mufflers in one. One setting to keep your neighbors happy and another to impress everyone on the street. Love them!!! I'd write more but time to warm them up and hit the street!


            Year: 2006 Submodel: GT

            Helpful (13)

          • 5/5

            Installation Time: Afternoon

            July 23, 2014

            I just did not realize

            These varitune mufflers are phenomenal! Not only can I open them up for a nice full sound, I can tune out the drone! I had the American Thunder Outlaw Series on the car before and it was loud all the time. I needed something to quiet the car down but still give me that nice rumbling sound I crave. These work like a champ! Install was easy enough. Made for adjusting the bracket and getting the exhaust to sit right a breeze. One tip had some burs on it the kept it from going on easy buy it was a quick fix with a file. Overall th we yet great for that everyday drive and when you want to thrash it around a bit. Highly recommended!


            Year: 2006 Submodel: GT Stavanger, Norway

            Helpful (13)

          • 5/5

            Installation Time: Afternoon

            April 14, 2014

            very easy to install in my garage in under 2 hours

            So easy to go back and forth between 3 stage and 1 stage ( in my opinion keep it in 1 stage all the time and try not to obnoxious to your neighbors ) . Didn't realize my car could sound so good with so little effort and little cost . I've told everybody who'd listen about this product and who sells it .


            Year: 2005 Submodel: GT Sunnyvale , cal.

            Helpful (13)

          • 5/5

            Installation Time: Less than 1 Hour

            February 26, 2014

            This product has Awsom sound

            These mufflers are great,its fairly quiet when closed ( for nabers) Then i went to the dragsrip and Open them up changed my tune to race, thay work great, only 5 open or close. the fit was perfect. resonable pricing. 09 mustang gt Thanks


            Year: 2009 Submodel: GT Hollywood, FL, USA

            Helpful (14)

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