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MAC Boom Tube Axle-Back Exhaust (15-20 EcoBoost Fastback w/o Active Exhaust)

Item 389972A
AmericanMuscle no longer carries the MAC Boom Tube Axle-Back Exhaust (15-20 EcoBoost Fastback w/o Active Exhaust). Please check out 2015-2020 Mustang Axle-Back Exhaust & Mustang Ecoboost Exhaust for an updated selection.

Features, Video & Details

  • Loud Throaty Exhaust Note
  • Resonator Tips
  • Muffler Delete Design
  • Mandrel-Bent 304 Steel Construction
  • 4" Polished Stainless Tips
  • Not Compatible with Active Exhaust
  • Fits 2015-2020 EcoBoost Fastback Mustangs

Review & Installation Video

Review & Install Video

Stephanie: Hey, guys. Stephanie with here with my review and install of the MAC Boom Tube Axle-Back Exhaust for the 2015 and up S550 EcoBoost Mustang. We're going to be talking about a few different things with this exhaust today, but mainly, we'll talk about the sound of the axle-back and the install. The install for this is gonna be easy. It's a two out of three wrenches on the Difficulty Meter since there is some cutting involved, but I'll get more into that later. The MAC Boom Tube Axle-Back Exhaust is gonna be a good option for the S550 EcoBoost owners out there that are looking for a loud and aggressive sound from a muffler delete axle-back system. This is one of the more budget-friendly options as far as axle-backs go, but it produces a good sound that isn't over-the-top, and it's made from 304 stainless steel as well. I'm gonna be honest here. A lot of times, a muffler delete system like this one here is just a little bit over-the-top on an EcoBoost, in my opinion. It's overly loud and it's just noise to me. The MAC here isn't like that. The system is definitely louder than stock and deeper, but it's not an uncontrolled loud. It really wasn't as loud as I thought it was gonna be, but I don't think that's a bad thing. It has a nice, deep tone and a good level of volume and even some crackle on decel, but not too much, so it just adds to the overall sound that this produces. I will say that while this system isn't really all that loud, it is just an axle-back, so you are maintaining your stock midpipe and you're still catted. This system, like any axle-back, can and will get louder if you modify your exhaust further, but as it sits right now, since this isn't the loudest axle-back out there, I'm gonna call this a three out of five on the Loudness Scale. One being a very quiet upgrade, and five being very loud. There are some quieter axle-backs out there and also some louder ones as well if this one isn't what you're looking for. A lot of aftermarket axle-backs open up turbo noise on the EcoBoost and this one is no different. You get a ton of blow off and turbo spool with this axle-back, and honestly, I don't think that that's something you can get away from with the EcoBoost. You're opening up that turbo and as a result, you make it more noticeable. This axle-back does have a muffler delete design, so it obviously has no mufflers. It has resonator tips instead. The tips are perforated baffles that control the exhaust note and they work to keep down the popping sound that you end up getting with a lot of other muffler delete systems. Eliminating the mufflers is going to eliminate a lot of the restriction that you normally get with a traditional-style muffler and reduce some back pressure. This is a two-and-a-half-inch system that's made from mandrel-bent 304 stainless steel and it doesn't get much better than 304 stainless. Stainless steel has advantages over other materials like aluminized since it's going to hold up much better over time and has great corrosion resistance. This system has four-inch polished stainless steel tips and because this is that muffler delete system, it has resonator-style tips. You can see that these are longer tips than what you normally see. And speaking of that, this entire system is a little bit longer than what you normally see. Normally, an axle-back is a little bit shorter than this, but MAC gives you longer pipes here. As far as price, this system is one of the more budget-friendly systems that are currently available. You can expect to pay between $400 and $500 for this, even though it is that high-quality stainless steel. But even so, this is more of a muffler delete system, so it has less of the expensive material than a normal muffler setup would have. One thing I don't like about this system, though, is the clamps that come with it. If it were me, I would go get a better clamp than this, but I am a little bit picky. But that's the downside of going with a more budget-friendly system. You miss out on some of the nicer qualities you get with the higher-end options. We're gonna be looking at the typical cut-and-clamp design with the install for this axle-back since you need to cut all S550 axle-backs. I'm gonna call this a two out of three wrenches on the scale, but just because of the cutting that's involved. It's nothing difficult, but I just recommend some eye protection and a fresh blade to make the cutting easier. Overall, you're looking at about two hours to get this done. A lift would certainly make things easier for you here, but the job can be done on jack stands as well if you don't have access to one. Cutting the factory axle-back isn't hard. Just be sure to measure twice and plan to mark where you'll be cutting so you don't make a mistake. This axle-back, like I mentioned earlier, is a little bit different than most and you will be cutting farther up, right after the factory midpipe. The new axle-back does come with new clamps for use, so you don't have to worry about that, and when you go to install your new setup, it'll probably best to leave everything loose until you have it all lined up, and then tighten it down. All right, guys. Wrapping things up here with the MAC Boom Tube Axle-Back Exhaust, this is a full 304 stainless steel system for the S550 EcoBoost that offers a good amount of sound. It is a muffler delete axle-back system, but it's not overly loud, in my opinion. As always, I suggest you guys check this out more online for yourself, and for all things Mustang, keep it right here at

"The Boom Tube". Uncork the exhaust of your EcoBoost S550 Fastback Mustang with a MAC Boom Tube Axle-Back Exhaust. This MAC Performance Axle-Back System eliminates the restrictive factory mufflers to reduce back pressure for an increase in both power and sound.

Resonator Tips. Often imitated but never duplicated, the MAC Boom Tube Axle-back Exhaust uses uniquely designed dual wall resonator tips that feature perforated baffles to provide a loud throaty exhaust note without the irritating popping of the imitators.

Durable Steel Construction. Constructed from 2.5" diameter mandrel-bent 304 stainless steel tubing, the Boom Tube axle-back system features polished 4" angle cut stainless steel dual wall tips for impressive muscle car styling and sound.

Cut & Clamp Installation. The installation of this Axle-Back Exhaust system will require cutting and removing the factory muffler assemblies and clamping the new muffler assemblies in place. Clamps and instructions are provided.

Application. This MAC "Boom Tube" Axle-Back exhaust system is designed to fit 2015-2020 EcoBoost Fastback Mustangs without the Active Valve Exhaust.

Not compatible with convertible models.

Please Note. MAC Performance does

not make any claims that their Boom Tube exhaust will meet any federal or local noise regulations or laws. Please check your local and state ordnances for installation and usage regulations.

Fitment: Details

CA Residents: WARNING: Cancer and Reproductive Harm -

What's in the Box
  • (1) Right Muffler Assembly
  • (1) Left Muffler Assembly
  • (1) Right Tailpipe Assembly
  • (1) Left Tailpipe Assembly
  • (4) Clamps
Installation Info
Tech Specs
Axle-Back Exhaust Specifications
Piping Material: Stainless Steel Tip Material : Polished Stainless Steel
Tip Size: 4" Fitment: 2015-2017 EcoBoost
Muffler Type: Straight Through / Resonator Fastback or Convertible: Fastback
Will it fit my Mustang?

    Customer Photos (1) Submit Your Photo

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      Questions & Answers (8)

      5 Top Rated Questions

      Did they change the tip design? My body shop ordered a new set of these and received the rolled edge rather than the straight cut that i got back in early 2018.

      • The product picture should be indicative of exactly what your item will look like upon purchase. If you receive something of which you did not order, please contact our customer service line right away.

      Helpful (0)

      Hi, Will this fit on a convertible if I only use the axle-back portion of the exhaust that includes the tips and not the back pipes?

      • Unfortunately this exhaust will not fit convertible models due to the different bracing. Only EcoBoost fastback models

      Helpful (0)

      From this exhaust system VS Borla cat back ATAK which one is louder

      • The MAC Boom Tube Axle-Back Exhaust and the Borla ATAK Cat-Back Exhaust, item # 387468, ( are both very loud and throating exhaust systems. The ATAK is going to be a bit more aggressive compared to the MAC system.

      Helpful (0)

      Can I get these with black tips for my V6, I see the GT has a black tip version, but there isnt one for the V6. Would the GT model fit my V6?

      • It does not look like we offer a version of the MAC Boom Tube Axle-Back with black tips. This looks to be the only version we have available for the V6.

      Helpful (0)

      Because this muffler has a muffler delete design, would I lose pressure in the back as if I had a muffler delete or it won't affect the pressure?

      • It's possible that you will lose back pressure, however every Mustang reacts differently in terms of back pressure when changing/modifying exhaust. Unfortunately there isn't a formula to follow when it comes to back pressure and exhaust, which means you may gain a little power, lose a little power, or notice nothing at all, and the only way to find out is to install it.

      Helpful (0)
      Post Your Question
      3 More Questions
      In the Fitment Section it states "Fits Fastback Models Only" Will this NOT fit a 2015 convertible EcoBoost? If not, why? 1 answer
      Would this connect to BBK X pipe 1 answer
      Would this connect directly to a 2.5" x or h pipe? 1 answer

        Customer Reviews (5) Write a Review

        Overall Rating 4.8

        out of 5 stars

        Installation Time:Full Day

        Installation Cost:0-$100

        • Loudness / Volume 3.8 3.8
        • Exhaust Note 4.6 4.6
        • Fit & Finish 4.4 4.4
        • Bang For Your Buck 4.2 4.2

        • 5/5

          Installation Time: Less than 1 Hour

          July 02, 2019

          Beautiful tone

          The tone is deep and wonderful to the ear. Not to loud for the neighbors but you can definitely tell it’s no ordinary mustang. Give it some gas and it has heads turning . Took less than an hour for the shop to install.


          Year: 2019 Submodel: EcoBoost

          Helpful (0)

        • 4/5

          Installation Time: Less than 1 Hour

          February 04, 2018


          I love the sound. Not as loud as I thought it would be but still gives a great tone. The clamps are worthless and has to be modified a bit to sit right.


          Year: 2016 Submodel: EcoBoost

          Helpful (13)

        • 5/5

          Installation Time: Shop Install

          Installation Cost: 0-$100

          September 21, 2017

          Review from MAC Boom Tube Axle-Back Exhaust (15-17 V6 Fastback)

          Worth the money

          LOUD sounds very good well worth the money only took shop half hour to put on and they also look nice.


          Year: 2016 Submodel: V6

          Helpful (12)

        • 5/5

          November 20, 2016

          Review from MAC Boom Tube Axle-Back Exhaust (15-17 V6 Fastback)


          These are a muffle delete so they will be loud. But a hot loud! Sound nice! Wow I can't believe how nice these sound! Drone is very very low!


          Year: 2017 Submodel: V6

          Helpful (13)

        • 5/5

          Installation Time: Shop Install

          Installation Cost: 0-$100

          October 05, 2016

          Straight Piped Sound.

          It is an over all good exhaust, it does sound a little funny on a cold start but after warming up you can love that nice turbo hum. Also like when you speed up you can hear the air being forced out the exhaust kind of resembling the sound of a turbo on a diesel truck.


          Year: 2016 Submodel: Ecoboost

          Helpful (13)

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