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Flowmaster Outlaw Axle-Back Exhaust with Black Tips (18-20 GT w/o Active Exhaust)

Item 404841-A
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      Review & Installation Video

      Hey, guys. It's Sara with And today, we have a review and install the Flowmaster Outlaw Axle-Back Exhaust with Black Tips, fitting your '18 and newer Mustang GT without the active exhaust. This powerful axle-back exhaust offers that raspy muscle car sound that you're looking for courtesy of Flowmaster's Outlaw mufflers. This exhaust is constructed from 3-inch mandrel-bent tubing and finished off with these 4-inch ceramic coated black tips. So as far as sound goes, I'm giving this exhaust option of four out of five on the loudness meter. This does feature Flowmaster's loudest muffler option, but it does still keep the resonator intact so it takes a little bit of that edge off and it's not quite a straight pipe system.This is gonna be for the Mustang owner who wants to save a bit of money over a full cat-back system. Maybe they already have an X or an H-pipe installed or you just really like the sound of that factory resonator but you're still looking for one of the loudest axle-back options out there. Coming in at around $600. This is one of the most budget-friendly options you can choose for an exhaust for your Mustang. I'm giving this install a two out of three wrenches on the difficulty meter. It does require some cutting for install, but it can be done within two hours. So with that said, let's hop right into our install.For this install we use an exhaust hanger removal tool, reciprocating saw, cut-off wheel, flathead screwdriver, extension, 13-millimeter socket, a deep 15-millimeter socket, tape measure, eye protection, a marker, a hammer, an impact gun, and an angle grinder. All right, so the first step in our uninstall is to grab a 15-millimeter socket and loosen both the nuts on each of these pipes. Next up we're gonna remove these hangers from the subframe, you're gonna want a 13-millimeter socket and an extension, we're just gonna go right over top of the sway bar. Now you can lift up and flip these out of the way. At this point, we can separate the exhaust from these two clamps that we loosened earlier. You may want to mallet as this will make it a little bit easier to get them off.All right, now that we have our factory exhaust uninstalled from the Mustang, we can put it side by side with the Flowmaster exhaust, really check out some of the similarities and differences. Now as you can see, we do reuse a portion of the factory exhaust around this resonator, so we're really only replacing the back muffler section. Flowmaster upgrades this section with 3-inch piping when compared to your factory two and a half and they utilize these Outlaw mufflers which have a straight-through design and are gonna be quite a bit louder than factory, and they finish it off with these nice black tips, they're gonna upgrade the rear of your Mustang.All right, so we have our factory exhaust here and we put our axle-back up next to it so we can get an idea of where to cut. Now we're gonna want to cut five inches back from this bend here, which does put it right in the middle of this heat shield. So we will have to cut this heat shield off before we can cut our piping. So to do that, we have a cut-off wheel here and we're gonna start by cutting off the band that holds on this heat shield on the bottom, we need to do this on both sides.Next up we're gonna make a cut right back here on the weld so that we can flip this heat shield up and break it loose. All right, so now that we've made our cuts back here by the weld, we're just gonna pry underneath the corner here, can use a flathead or your hands and just rock it back and forth until we're able to break it loose. All right, now this portion is optional. If you'd like, you can grind down this weld a little bit just to take some of the sharp edges off but because your pipe is gonna slip a little bit farther back you don't need to do this.All right, so next up we're gonna measure five inches back from this bend on the street section, comes to about there. If you're not sure, you can lay your axle back over and just double-check. We're gonna make our mark. Now at this point you can cut where you made your mark. So now once you've made your cut, if there's any burrs around the piping, it does need to slip into the axle-back section, so you might want to just clean those up a little bit to make it a little smoother. All right, so now that this side is complete, we're gonna repeat that process on the other side of our piping.All right, once our cuts are complete, we can reinstall the resonator section on our Mustang. Now if you have taken these clamps off, make sure you put them back at this point. All right, so before we get our axle-back section bolted up, we want to reinstall the factory brackets with the rubber bushings over top of this hanger. Next up, we want to get the exhaust installed in this hanger at the back. Don't have to worry about how much for now, just enough to have it supported so we can get the piping attached.All right, so before you get your piping attached, make sure you get the exhaust clamp on there. Now we can go ahead and align our piping. Finally, make sure that the hanger you installed before is lined up on the subframe. Repeat that process on the other side. Now we're gonna replace the factory bolts. Grab your 13-millimeter socket and tighten these down. Now we can tighten the clamps on our exhaust starting at the very front. Grab a 15-millimeter socket and tighten these down. Now we got the clamps in place on your axle-back sections. Brab a 15-millimeter socket and tighten them down.All right, so that's gonna do it for the review and install of our Flowmaster Exhaust. Remember for all things Mustang, keep it at

      Product Information

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


      • Powerful Outlaw Series Axle-Back Exhaust
      • Offers a Raspy, Muscular Sound
      • Two Flowmaster Outlaw Mufflers
      • 3-Inch Mandrel-Bent Tubing
      • Durable Stainless Steel Build
      • Two Hardcore Black Tips
      • Moderate Skills Required for Installation
      • Limited Lifetime Warranty
      • Fits All 2018-2020 Ford Mustang GTs without Active Exhausts


      Top-Notch Sound. Created to be used at tracks that require mufflers, but don't have any DB restrictions, Flowmaster's Outlaw Series Axle-Back Exhaust with Black Tips will immediately enhance your 2018-2020 Ford Mustang GT's sound. This exhaust is designed to produce a raspy, muscular sound that perfectly matches your Mustang's aggressive performance to turn heads wherever you go.

      High-End Function. Not only does this impressive Outlaw Series Axle-Back Exhaust manage to dramatically improve your Mustang's sound, but it also produces more power than open headers to enhance your Pony's overall performance. Featuring a boost in horsepower and torque, this exhaust ensures you remain at the front of the pack on the track and in the street.

      Maximum Durability. With 2 of the smallest and lightest race mufflers to date, as well as 2 hardcore yet undeniably sleek and stylish black tips, this Outlaw Series Axle-Back Exhaust is designed to impress. The exhaust is also constructed from 3-inch mandrel-bent stainless steel tubing that is created to stand up to continued abuse so you can rely on its ideal performance for a long time to come.

      Installation. Using moderate mechanical skills, this exhaust can be secured easily. Just set aside about 1 hour for the installation.

      Warranty. Featuring a limited lifetime warranty, this exhaust is protected against defects. Some limitations apply, so check out the full warranty for details.

      Application. Flowmaster's Outlaw Series Axle-Back Exhaust with Black Tips perfectly fits all 2018-2020 Ford Mustang GTs without Active Exhausts.

      Fitment: 2018 2019 2020 Details

      Flowmaster 817806

      CA Residents: WARNING: Cancer and Reproductive Harm -


      Customer Reviews (16)

      Write a Review

      Ratings Summary

      5.0 out of 5 overall rating from 16 customers

      Installation Time: Afternoon

      Installation Cost: $100-$250

      • May 13, 2020

        5 2019 GT - youdid Installation Time: Afternoon

        One of my favorite mods!

        2019 GT Premium Perfoance Package. The sound is incredible. Nasty when you want and calm at low rpm. No droning issue

        Helpful (0)
      • April 16, 2020

        5 2006 GT - JaimeT Installation Time: Shop Install

        Flowmater outlaws

        These will wake up that true mustang sound and it will also give great performance gain! I get compliments everywhere i go! 5 star for sure

        Helpful (3)
      • March 04, 2020

        5 2019 GT - DBakes Installation Time: Less than 1 Hour


        Louder than stock but barely noticable at cruising speeds. Can definitely hear it at WOT though!

        Helpful (3)
      • January 16, 2020

        5 2019 GT - JLJenkins Installation Time: Less than 1 Hour

        Beyond Amazing Roar!

        Purchased this for myself as a Christmas present along with some a Roush H Pipe. My brother and I installed last Sunday and the combo of this and the H pipe is deafening. So long baby rumbling when I floor the pedal. Now you can hear me a mile away!! Definitely recommend!!!

        Helpful (4)
      • November 20, 2019

        5 2018 GT - Anonymous Installation Time: Less than 1 Hour


        Amazing tone and extremely noticeable improvement over the factory exhaust ! 11/10 would recommend!!

        Helpful (4)
      • October 15, 2019

        5 2018 GT - GritzNrice Installation Time: Shop Install Installation Cost: $100-$250

        Great bang for your buck

        I got these installed yesterday at a muffler shop and they are loud. I have the resonator delete x pipe on it as well. It does drone a little but when you punch it, you can hear it roar. It does quiet down when idling but you still hear a little rumble. Overall these are great. The black tips add more to the loo too. I would recommend these.

        Helpful (7)
      • September 22, 2019

        5 2019 GT - Jtart Installation Time: Less than 1 Hour


        If you want to wake the neighbors this is for you. These are mufflers, just barely. Granted it’s not the Fox body h pipe flowmaster sound it’s a new ballpark with these. Happy with them, although if you don’t want obnoxious I’d keep the resonator just in case.

        Helpful (3)
      • September 03, 2019

        5 2019 GT - MaverickS550 Installation Time: Less than 1 Hour

        Outlaw for the Win!

        Very aggressive sound especially at WOT absolutely love it

        Helpful (3)
      • June 02, 2019

        5 2018 GT - Sodatoxicity Installation Time: Afternoon

        Best sound for the money

        Great sound, low to almost no drone in interior, 2 small kids no complaints on inside

        Helpful (3)
      • May 24, 2019

        5 2018 GT - Brandon Installation Time: Shop Install Installation Cost: $100-$250

        Sound great

        My son wanted exhaust that was obnoxiously loud under full throttle and this is it. Don't drone too bad during regular driving. Sound great at idle. Black tips look awesome

        Helpful (4)

      Questions & Answers (4 answers)

      4 Top Rated Questions

      I currently have the Magnaflow Competition Cat-Back Exhaust system installed, but will these axle-backs work with that set-up if I wanted to change to these?

      • Between the two muffler sets, we would be comparing really loud, with really really loud. However, the really really loud would be the Flowmaster, so if you wanted even a bit more sound coming out of those tail pipes, this would be the way to go.

      Helpful (1)

      Hey there! Any idea how much this and the flowmaster x pipe resonator delete would increase horsepower on a ‘19 gt? Thanks

      • When it comes to exhaust, unless you're talking about headers, you really aren't going to get any power gains. This will be manipulating the sound way more than power. Any power change there may be would likely be negligible as well.

      Helpful (0)

      Hello American Muscle! I have a Mustang GT 2018, Would i have to tune this Flomaster Outlaw Axle-Back Exhaust, i have everything stock in the exhaust. Any Help Please!

      • This does not require a tune.

      Helpful (0)

      Will this fit if I have a Roush H pipe installed?

      • Yes, being as this is designed to work with an otherwise stock Mustang, and the H-pipe is designed to work with an otherwise stock Mustang, it would indeed be safe to say these would be compatible.

      Helpful (0)
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      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (1) Driver Side Muffler Assembly
      • (1) Passenger Side Muffler Assembly

      Will It Fit My Mustang

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