MRT Axle-Back Exhaust Kit KR Stainless Steel With 4" Polished Tips Without Active Exhaust Mustang V6/ EcoBoost 2015-2021
MRT Stainless Steel KR Axle-Back Exhaust Kit with 4" Polished Exhaust Tips for 2015, 2016, 2017, 2018, 2019, 2020, and 2021 V6 and EcoBoost Mustangs without the Factory Active Exhaust Option.
California Residents: Proposition 65 Warning
Novice skill is required for this installation.
The MRT KR series is a light-weight, USA made, 304 stainless steel, muffler delete. Features a 4 inch polished tip, and like all axle-backs, will require cutting for installation. This is going to fit your fastback or your convertible.
For this installation today: lift or jack and jack stands, 1/2 inch ratchet, 15mm socket, tape measure, marker, sawzall, and safety glasses.
Like we said before, this axle-back will require cutting your stock exhaust to install it. Viewers of our channel are going to know, our stock exhaust is long gone from our EcoBoost Mustang. Basically what you're going to do, is where the factory muffler curves into the tail pipe, 2 inches over from the curve, you're going to mark it, and cut it straight off.
The pipe almost has a mark where you want cut. Follow the edge of the curve where it's flat, make a little mark, and that's where we're going to cut.
You want to make sure once you cut it just go back through, just de-burr it real quick, make sure there's no sharp edges.
Once you have it cut just clean up the edge, and the installation's pretty easy. Take your clamp and slide it over the factory pipe, and take our MRT KR just put it just on the edge of the factory hanger here, push back till it lines up with the pipe, and slide it over.
Once you have it adjusted in place, slide the clamp over, and tighten it down. Repeat the process on the other side and your installation's finished.
All right, now let's see how our MRT KR's sound. Definitely a deeper tone a idle. Definitely one of the louder, more aggressive sounds we've had, especially considering we have the stock catalytic and the stock resonator still on this car.
Despite how loud it is outside, the MRT KR actually isn't that bad inside. You can hear it, it's a nice deep tone, but even accelerating, I mean it's loud, but it's not nowhere near as bad as I thought it would be. That's kind of the case with all the S550 exhaust systems though. These cars are so well insulated inside that no matter how loud the exhaust is, it really isn't bad inside the car.
Now we're up to highway speeds, we're cruising right at just under 2 grand, let me get it right at 2 grand. That's 2000 rpm's, no drone at all, barely even know it's back there. I found the EcoBoost cars, especially if you keep the factory resonator in place with the factory down-pipe with the cat, there isn't a bad drone to them.
Wide open throttle sounds good. Again, like I said, not overly loud inside. I know from our original video clip that it is loud when you're actually revving it up inside the studio or even sitting outside, but when you're driving along, it's not bad at all.
If you're looking for the loudest muffler you can find for your EcoBoost Mustang, yet still want to keep the resonator and the catalytic converter to stay legal, the KR from MRT is probably the way to go. These things are loud and aggressive, really not that bad when you're driving on the highway. The installation, besides the cutting, is pretty straightforward. Even with the cutting, the whole process should only take you about an hour, so you'll be back on the road in no time. For more solution videos for your 2015 Mustang, make sure to subscribe to our YouTube Channel, and check out cjponyparts.com for the best selection of 2015 Mustang parts.