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Flowmaster Outlaw Axle-Back Exhaust (11-12 Mustang GT, GT500)

Item 18422
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Ship to: Ashburn - 20149
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      Video Review & Installation

      Justin: Hands down, the Flowmaster Outlaw will be one of the loudest axle-backs in the category for '11 to '12 Coyote and Shelby owners alike who want to be heard by everyone and have no remorse for other cars, neighbors or eardrums around you. Now the Flowmaster will pack 409-grade stainless steel throughout for the mid $400 price point while the installation will get a very soft two to three wrenches on the difficulty meter and hopefully an hour to complete from start to finish as we'll show you later in the video. But since this is an exhaust video after all, what do you say we break down the sound clips you guys just heard with our 5-Liter GT? And as advertised, the Outlaw is an absolute punisher, one of the loudest systems I've personally heard on the 5-Liter Coyote and an easy five out of five on my one to five or one to wake-your-neighbor scale. And while, yes, this thing is loud on the inside, you are getting a decent amount of noise inside the car as well. And that's something some owners should take into consideration. And some owners might like, others may not. Now if you do have your heart set on that iconic Flowmaster sound, but maybe aren't ready for all of this volume, you might want to check out some of Flowmaster's other offerings instead which will be a tad bit tamer.Now one thing I always like to mention in axle-back videos, and one thing I think it is important for you guys to consider, is that what is your future plans with your car or exhaust. Because as loud and angry and unruly as this thing is right now, you have to keep in mind that is with the factory manifolds or headers still in place. Now remove those manifolds in place of some long tubes, catless, whatever, and that sound is only going to get louder and crazier. Now if you're cool with that, great. You're certainly going to be in the right place. However, if the current volume level of the Outlaw just with axle-backs alone is, kind of, tiptoeing on being just a bit much, well then, it is only going to get louder in the future with more exhaust modifications, so, again, just something for you guys to consider at home. But what do you say we talk about why the Flowmaster Outlaw is such a head-turner in the volume department and, honestly, I can speak to this from experience as I've actually assembled one of these systems at the Flowmaster factory out in California.Now the Outlaw body itself starts out life as a 4-inch piece of tubing, and then is stuffed with four to five metal baffles and then welded into place one at a time. Now these baffles do have a hole right in the middle allowing for better flow along with, of course, all of that volume. Now, as far as the rest of your construction is concerned, well, you're gonna be looking at 409-grade stainless for a majority of your build here, which is a step up from the aluminized steel when it comes time to reducing corrosion over the years, even more so with the black paint on top here which is, kind of, a signature Flowmaster move.Now the Outlaw Axle-Back does feature mandrel-bent 2 3/4-inch tubing and everything is going to exit out the twin 4-inch tips here embossed with that Flowmaster logo. But now comes the time in the video where we want to show you just how to get everything bolted up on your ride at home. So, without further ado, here's a detailed walkthrough along with the quick tool breakdown.Male: Tools used for this install are an impact gun or ratchet, a small extension, a 13-millimeter socket, and a pry bar.So the first step of this install is going to be removing your factory mufflers from the car. There's only a couple of hangers and a couple of clamps that hold them in place and they should come out relatively easily. So let's get started. So the first thing I'm gonna do is loosen up and remove the ballplayer clamp that is on the inlet pipe to the muffler and I'm gonna use a 13-millimeter socket on my impact gun to loosen that up.So, in order to remove this muffler, I'm gonna have to unbolt the front and rear hangers from the vehicle. Some of the bolts are a little bit tricky to get to, so I'm going to use a pry bar and push my muffler back as far as it'll go just so I can get better access to the bolts. And then I'll move to the back hanger of the muffler. All right. So next, what I'm gonna do is remove this hard-to-reach bolt that is on the inside of the bumper along the frame rail here at the back of the muffler. I'm gonna use a 13-millimeter socket and unbolt it from the car. Next, I'm gonna get this lower bolt also with a 13-millimeter socket. And now I can pull the muffler out of the rear hanger and remove the muffler. Now I'm just gonna repeat this process on the other side. I'm gonna unbolt my clamp, unbolt my hanger in the front and unhook my hanger in the rear.So the next thing I want to do here is remove my hanger from my muffler, and I'm just gonna slide that off of the hanger rods and I'm gonna install it onto my new muffler. I'm just gonna slide that on in the same orientation and then I'll bolt it all onto the vehicle. Then I'll just repeat this for the other muffler. I'm now ready to throw these onto the car. I'm gonna start by inserting the hanger rod into the rear hanger just to hold everything up, and then I will position my front hanger and insert my hardware. Now I can tighten up that hardware. Now I'm ready to position my over axle pipe to the inlet of my muffler and then get my clamp into place. Then I'm just gonna use my 13-millimeter socket on my impact gun and I'm just gonna lightly tighten it down and then make my adjustments. Now that I have my tip adjusted the way I want it, I'm just gonna take my 13-millimeter socket again and tighten up the clamp fully. Now I'm just gonna repeat the same exact process on the other side.And that's gonna wrap up this review and install of the Flowmaster Outlaw Series Axle-Back Mufflers for your '11 to '12 Mustang. Thanks for watching. And for all things Mustang, keep it right here at

      Product Information

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

      Features & Specs

      • Super Aggressive Flowmaster Outlaw Sound
      • Durable 409 Stainless Steel Construction
      • 2.75" Mandrel-Bent Tubing
      • 4" Polished Stainless Steel Tips
      • Includes Two Flowmaster Outlaw Mufflers
      • Fits 2011-2012 GT, Boss and 11-12 Shelby GT500


      Super Aggressive Flowmaster Sound. Give your Coyote powered Mustang that unmistakable Flowmaster sound with the Outlaw Series Axle-back exhaust system from AmericanMuscle. This system improves exhaust flow using Flowmaster's race-oriented style Outlaw mufflers for that super, aggressive exhaust note your high powered Pony deserves.

      Stainless Steel Construction. Constructed from durable 2.75" 16 gauge 409 stainless steel tubing for it's corrosion resistant properties the Flowmaster Outlaw Axle-back features two race-oriented mufflers with massive 4.0" diameter polished stainless steel tips for impressive muscle car looks and sound. As an added bonus the tips are embossed with the "Flowmaster" logo for true custom styling.

      Application. This Flowmaster Outlaw Series Axle-back exhaust system is designed to fit the 2011-2012 GT, Boss and the 2011-2012 Shelby GT500 Mustangs for both great looks and great sound.



      Flowmaster 817516

      CA Residents: WARNING: Cancer and Reproductive Harm -

      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (2) Muffler assemblies
      • (2) 3/8" Hanger Keepers


      Customer Reviews (500+)

        Questions & Answers

        10 More Questions

        Will It Fit My Mustang

        • Boss 302 - 12
        • GT - 11, 12
        • GT500 - 11, 12

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