“Mystery Mufflers” vs. Roush Axle Backs - Exhaust Comparison

DudeStang

Nuts fell off while driving
5 Year Member
Apr 30, 2017
635
353
83
I picked up these axle backs second hand a few months back. Nobody really seemed to know where they came from (seller wasn’t sure either) so I’ve started calling them the “mystery mufflers”. This past weekend I installed them on my 2014 GT and made a video of the install and a sound comparison between these and my Roush axle backs.
96885B66-7921-4FE6-9066-D2A9A25E2192.jpeg

I did some searching and they bear slight resemblance to the flow master outlaws and the American Muscle SR performance axle backs but not close enough to either to be a confirmed match IMO.
366FC842-5800-4B02-8B34-241AE94D96E6.jpeg A996B842-4A60-4315-A9DF-5C3A86772225.jpeg

Anyways, here’s the video. Let me know what you think or if you have any theories. Thanks.


View: https://youtu.be/bruvGnGuAHk
 
Last edited:
  • Sponsors (?)


What size are those, 3"? Almost look like they might be Dynomax Race Bullets (they do sell a Race Bullet axle back, only place I think I've ever seen it being sold is Rock Auto). Either that or it's something that was cobbled together, not sure.
Ah, thanks. I hadn't looked at those yet. I just did a search and it definitely looks similar.
 
So for sh*ts and giggles, I put the stock mufflers back on over the weekend. I couldn't believe how quiet it is. First time I've been able to have a conversation while driving without raising my voice in almost six years. After driving it around a little bit, I think I'm leaning towards selling both the Roush and the mystery mufflers and going with the GT500 ABs, lol.


View: https://youtu.be/9bgLVbNhkA4
 
I had race bullets on one of my old cars years ago and they were loud as :poo: so I'm not surprised. With mufflers like that you almost have to have some kind of resonator to take the edge off. I'm running small "glasspack" resonators with my MBRP's and it's just enough to make them mostly tolerable for daily use.
 
  • Like
Reactions: 1 user
I had race bullets on one of my old cars years ago and they were loud as :poo: so I'm not surprised. With mufflers like that you almost have to have some kind of resonator to take the edge off. I'm running small "glasspack" resonators with my MBRP's and it's just enough to make them mostly tolerable for daily use.
Yeah man, I feel like my brain/ears are coming back to homeostasis after not being worn down by exhaust drone for the past week, lol. Way back in the day I had an LS1 TransAm with long tubes, an off-road y pipe, and SLP loudmouth catback. It was insane....armageddon rolling down the street. Even in my early 20s I eventually had to get a resonator to tone it down a bit.
 
What size are those, 3"? Almost look like they might be Dynomax Race Bullets (they do sell a Race Bullet axle back, only place I think I've ever seen it being sold is Rock Auto). Either that or it's something that was cobbled together, not sure.
Even if they don't sell axle backs any good muffler shop can make them easy enough. And I agree they look like Race Bullets. They look too wide and short to be Outlaws.
 
  • Like
Reactions: 1 user
Even if they don't sell axle backs any good muffler shop can make them easy enough. And I agree they look like Race Bullets. They look too wide and short to be Outlaws.
Yeah, at this point my assumption is that they are just a custom one-off done by a muffler or performance shop. I'm far from an expert but I do think the craftsmanship is really good...everything is solid/sturdy and it fits exactly how it should. Just a too much drone for my current "getting older" taste.