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BBK Varitune Cat-Back Exhaust w/ X-Pipe (15-17 GT Fastback)

Market Price $1,074.99 You Save 12% ($125.00)
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  • Item 389774

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    Features, Video & Details

    • BBK Varitune Cat-Back with "Adjustable Power Valve"
    • Change from a Three to One Chamber Exhaust for More Power and Sound
    • 8-10 Decibel Range Difference
    • Includes Resonator Delete X-Pipe
    • 4" Polished 304 Stainless Steel Tips
    • Fits 2015-2017 GT Fastback Mustangs

    Review & Installation Video

    Review & Install Video

    Hey, guys. Stephanie with, with a quick review and install of the BBK Varitune Cat-Back exhaust for 2015 and up, GT Mustangs. In this review, we're gonna cover a few different topics, but we'll mostly be talking about the sound of this cat-back and the install. Installing a cat-back on an S550 is an easy job, and this Cat-Back is no different. So, I can tell you right now that I'm going to call it a one out of three wrenches in the difficulty meter. This is a Cat-Back that's gonna be a good option for someone that will like more of an old school muscle car sound without having to pay an arm and a leg for it. Some Cat-Backs for the S550 GT are just plain loud. They have a ton of volume and noise. This Cat-Back isn't quite like that. Just like with the axle back version of the system, BBK was focused more on the quality of the sound. They also work in an option of going from a three-chambered muffler to a single chamber, which means that you can change your exhaust note as soon as you want. So that means this is a versatile system that can be quiet for those that want a nice quiet upgrade, or throaty for those that want something a little bit more. So, these mufflers have an internal adjustable power valve, and that's how they're gonna change in sound. When the valve is closed then the exhaust will be forced through all three chambers in the mufflers. When the valve is open, the exhaust can take the path of least resistance which is through a single chamber. That's gonna make the muffler straight through mufflers which is gonna be more throaty and have some more volume along with it. This means you can really personalize your exhaust system and choose which sound that you like better. Overcome or upgrade over the factory mufflers but still a big improvement, or as much volume as possible through the BBK system. And I will say that there is a difference between the closed and open positions of the mufflers. So, the Cat-Back does have an X-pipe as a mid-pipe which is traditionally gonna give a louder, raspier note. And we'll say that the Cat-Back is deeper than stock for sure when the valve is closed, and the exhaust is forced through all three chambers of the mufflers, but I'm not sure I'd really describe the system as extremely loud. It's louder than stock in all aspects and deeper as well, but overall pretty tame in my opinion when you compare it with some of the louder Cat-Backs. That's kind of what I expected here. Even with the valve closed, it does get louder in the higher RPMs, and for that reason I'm gonna rate this Cat-Back as a two on the scale when the valve is closed. That mid-pipe helps the system with volume and sound, both when the valve is opened and closed. With that being said, the rating is going to change when the valve is open, and like I mentioned earlier there is a difference in the sound. When the valve is open, it's going to open up some more growl and some more rumble and even some popping on Diesel, and a lot more raspiness. You're gonna notice a difference in the settings, and I'm not saying that's a bad thing, especially if you want a system that can be both tamed and be more rowdy when you want it to be. Another good thing about this system, is that you can hear that you have an aftermarket at Cat-Back on the car from inside of the cabin, but I wouldn't say that there's a lot of drone [SP], so this could be a good option for daily drivers. Even so, I would rate this as a three on the loudness scale. If you're looking for that aftermarket forceful sound, then I would recommend just opening the valve right away and going right for the loudest setting. And speaking of changing the internal valving, it's adjusted right here at this point on each muffler. Some of the other features of this system has a four-inch polished stainless steel tips, while the x-pipe is aluminized tubing, and the axle back itself is stainless steel. When it comes to price, you can expect to spend between $900 and $1,000 for this system. That puts us right in the middle of the pack with pricing, especially when you start to consider some of the bigger players like Corsa, Borla, and Ford Racing, coming in at over a thousand bucks. When it comes to the install, you're going to be looking an easy one out of three wrenches on the scale when we look at difficulty. This is considered a direct bolt-on item, so you won't need to cut anything or modify anything to get it installed. All that you're really gonna need is a socket set, and a lift would certainly make things easier, but the job can be done on jack stands as well. You're gonna be removing the exhaust from the resonator back, so an extra set of hands can make things easier for you here. You'll be moving the rear hangers to the new Cat-Back, so I'd recommend taking them off of the factory exhaust when you drop that, because it'll only make the swap a little bit easier. The only other thing you'll ever use is the front clamps off of the resonator for the front of the new Cat-Back. The whole Cat-Back can be dropped as one big piece, which is why I say that an extra set of hands can help you out. When you go to install your new setup, it'll probably be easiest to start from the front and move back. So, install in the pipe area first, then move back to the muffler assemblies. Now, we'll leave everything loose until you have it all lined up, and then tighten it down. The Cat-Back does come with new plans like I mentioned, so you don't have to worry about picking those up, and you can figure on spending about an hour or two from start to finish to get all this done. All right, wrapping things up for the BBK Varitune Cat-Back, this Cat-Back gives the option of running a quieter, three-chambered muffler, or you can open a valve from outside of the car with a turn of the wrench, and open up some more volume from a single chambered, straight through type of muffler. This system features an aluminized X-pipe with a stainless steel axle back that's easy to install, and you can check it out more on line right here at

    Adjustable Sound. BBK's Varitune Cat-Back Exhaust system features patented tunable performance mufflers that allow you to customize your 5.0L Fastbacks exhaust note from mellow to throaty with just a twist of a wrench, for a 8 to 10 decibel sound level difference! This cat-back not only sounds great, but also improves exhaust flow with the included X-Pipe for dyno proven gains up to 30 horsepower.

    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.

    Durable BBK Construction. Constructed from the high quality stainless steel the included Varitune chambered mufflers end with 4" polished 304 stainless tips for impressive good looks and sound. The X-Pipe is mandrel-bent from aluminized tubing with smooth bends throughout the entire piping to improve exhaust flow for more power and better performance.

    Application. This BBK Varitune Cat-Back Exhaust with Resonator Delete X-Pipe is designed to fit all 2015 to 2017 GT Fastback Mustangs equipped with a DOHC 5.0L coyote V8 engine.

    Fitment: 2015 2016 2017 Details

    MPN# 30065

    CA Residents: WARNING: Cancer and Reproductive Harm -

    What's in the Box
    • (1) Passenger side muffler assembly
    • (1) Driver side muffler assembly
    • (1) Passenger side intermediate exhaust pipe
    • (1) Driver side intermediate exhaust pipe
    • (2) Exhaust Tips
    • (1) X-Pipe
    • (6) Band Clamps
    Installation Info
    Tech Specs
    Cat-Back Exhaust Specifications
    Piping Material: 304 Stainless Steel Tip Material : Polished 304 Stainless Steel
    Piping Size: 2.5" Tip Size: 4.0"
    Muffler Type: Straight-through Fitment: 2015-2017 GT Fastback
    Will it fit my Mustang?

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    Questions & Answers (5)

    5 Top Rated Questions

    How do you select the variable modes?

    • There will be a bolt on the muffler assembly to change the valves from open to close on this exhaust.

    Helpful (0)

    The video says the tubing is aluminized steel. I currently live in Guam, which makes for an extremely corrosive environment and things tend to rust very quickly and easily; how well will this system hold up to corrosion? I would hate to spend $1000 on a non-stainless steel system only to have it rust a few months later. Thanks.

    • The BBK Varitune Cat-Back Exhaust w/ X-Pipe with coated in an Aluminized steel which will hold up well against most elements for years to come. However, if you are in a more harsh environment and have concern about it rusting, I would recommend looking more in to an exhaust system made With Stainless Steel which holds up against corrosion better than Aluminized Steel.

    Helpful (0)

    Will a BBK Ceramic Tuned Length Shorty Headers fit?

    • Hi, This BBK Varitune Cat-Back Exhaust w/ X-Pipe will work with the BBK Ceramic Tuned Length Shorty Headers as long as you still have the factory mid-pipe installed.

    Helpful (0)

    Can you say for sure that it will fit a 2015 GT Convertible.

    • Hi, This BBK Varitune Cat-Back Exhaust is only for 2015-17 Mustang GT 5.0.Coupes, because of the extra braces that support the convertible Mustang body.

    Helpful (0)

    Does this require a tune?

    • Negative

    Helpful (0)
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    Customer Reviews (1) Write a Review

    Overall Rating 5

    out of 5 stars

    Installation Time:Less than 1 Hour

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

    • 5/5

      Installation Time: Less than 1 Hour

      January 11, 2017

      Jekyll and Hyde!

      The easiest most secure mail order exhaust system I have EVER had the fortune of installing! Start up is actually a little louder with the mufflers active but it sure is a lot easier to communicate in the car on the road. Twist the adjustment acme thread out four inches, which is somewhat cumbersome thing to do only because of its location on the back side of the muffler, lock it down with the jam nut and instantly you have a screamin' demon!! It literally goes from something you can drive thru the neighborhood to something you might not wanna drive thru the neighborhood. VERY pleased!


      Year: 2016 Submodel: GT

      Helpful (11)

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