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Kooks Muffler Delete Axle-Back Exhaust (15-17 GT Fastback)

Item 386647
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      Video Review & Installation

      Hey, guys. Stephanie with, here with a review and an install of the Kooks Muffler Delete Axle-Back Exhaust that's available for the 2015 and up S550 GT Mustang. We're gonna cover a few things with this exhaust in this video. We'll mainly be talking about the sound of the axle-back, the materials, and the install. The install for this is easy. It's a two out of three wrenches on the difficulty meter, but only because you do need a cut in order to install an axle-back on an S550. But we'll talk more about that later.The Kooks Muffler Delete Axle-Back Exhaust is going to be a system that you should check out if you're looking to make a big change in your exhaust note while spending minimal dollars and still going with a top-of-the-line brand. Muffler delete axle-backs are more budget-friendly than normal muffler assemblies, so in this case, you're getting a ton of sound from a top-of-the-line brand and you aren't totally killing the bank account.So normally in an axle-back video, I would start talking about the mufflers right about now. In this case, we don't have any mufflers. Kooks made this muffler delete system in order to deliver an aggressive note that's loud and reduces the normal flow restriction that you get with a traditional muffler setup. All that you're looking at here is stainless steel tubing that bolts up to the factory piping, steps up to 3 inches, and ends with 4-inch polished tips. This is gonna make for a very big change in exhaust note. After the resonator, you're not gonna have any exhaust filtration whatsoever. As you heard in the sound clips, this is gonna be much louder than stock and deeper-sounding.The good thing about this axle-back, though, is that, if you want it to be tame, it can be, but it gets rowdy when you lay into it. It's nice, in my opinion, when you get a sound that changes like this one does. You get more of a range of tones and sound to enjoy, and you don't have to worry when you're idling or lightly cruising that your car's too low. You do come across a little bit of drone with this axle-back. It is a muffler delete system, so I'm personally not surprised by that fact. It's definitely not the worst drone that I've ever heard, but it is noticeable. And far as sound inside the car, you can hear that you have an aftermarket exhaust on the car, but you don't get the same sound on the inside. It's much more toned down. This makes the drone not that bad, so it's not a deal-breaker, in my opinion.That being said and after you guys heard the sound clips, I'm going to label this one as a four out of five on the loudness scale with one being a quiet upgrade and five being a very loud upgrade. For an axle-back, you can't get much louder than this. I will say, though, that you should keep in mind that you get this volume and this sound with the stock resonator still in place. If you ever change your mid-pipe down the road or even your headers, for that matter, this system's gonna get even louder, and it has the potential to be absolutely loud, depending on what you do with the rest of your exhaust system. Just keep in mind the smaller diameter inlet that this axle-back has, being that it's made for the stock exhaust.So I mentioned earlier that this axle-back is stainless steel. Stainless steel is the best option when it comes to exhaust if you're looking for corrosion resistance and a long life from the product. It's gonna have property advantages over other materials, like aluminized steel, and it's gonna hold up much better over life.Next, we're looking at price. If you wanna pick this axle-back up, you can expect to spend between $500 and $600. This is the least expensive Kook's system that you can pick up for your GT, but that goes back to what I said earlier about muffler delete systems being less expensive. This axle-back still has the same quality materials and construction that all Kooks systems have, so it isn't slacking there. There are other muffler delete offerings out there that cost less than this one here if the Kooks is out of your price range. You'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 not 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 all 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. And the new axle-back will come with new clamps for you, so you don't have to worry about that. When you go to install your new setup, it'll probably be easiest to leave everything loose until you have it all lined up and then tighten it down. Wrapping things up with the Kooks Muffler Delete Axle-Back system, this is a stainless steel axle-back that steps up to 3 inches. It's designed to be used with a factory exhaust or an aftermarket exhaust with the same diameter, and it delivers a ton of sound. As always, you guys can check it out more online right here at

      Product Information

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


      • Aggressive Muscle Car Sound
      • Improved Performance
      • Minimal Air Flow Restriction
      • Muffler Delete
      • OEM to 3" Stainless Steel Tubing
      • 4" Slash Cut Polished Tips
      • Fits 2015-2017 GT Fastback Mustangs


      Aggressive Exhaust Note. Give your S550 GT Fastback a loud, aggressive exhaust note by upgrading to a Kooks Muffler Delete Axle-Back Exhaust System with 4" Polished Tips. This axle-back will not only improve your exhaust flow, but will add more power to your 2015-2017 Pony.

      Durable Stainless Steel Construction. Constructed from 100% stainless steel for long life, this Kooks Axle-Back Exhaust System features free-flowing OEM to 3" stainless steel tubing and large 4" highly polished slash cut, stainless steel tips.

      This Kooks Muffler Delete Axle-Back Exhaust with Polished Tips is specifically designed to fit the 2015-2017 GT Fastback Mustangs in combination with the factory exhaust system. Cutting of factory exhaust is required for installation. Not compatible with convertibles.

      Technical Note. Not legal for use on pollution controlled motor vehicles; intended for off road use only.

      Shipping Note. This product can not be shipped to an APO/FPO, Guam or US Virgin Island addresses.

      Fitment: 2015 2016 2017 Details

      Kooks 11516400

      CA Residents: WARNING: Cancer and Reproductive Harm -

      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (2) Axle-Back Assemblies
      • (2) Polished Tips
      • (4) Clamps

      Tech Specs

      Axle-Back Exhaust Specifications
      Piping Material:Stainless Steel Tip Material :Polished 304 Stainless Steel
      Piping Size:OEM to 3"Tip Size:4"
      Muffler Type:Muffler DeleteFitment:2015-2017 GT Fastback

      Customer Reviews (3)

        Reviews of Kooks Exhaust products have an average rating of 4.8 out of 5

          Questions & Answers

          10 More Questions

          Will It Fit My Mustang

          • GT - 15, 16, 17

          Not compatible with Convertibles due to different bracing

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