Lethal Performance improves the tone of its Mustang GT with a Roush axle-back
A Mustang just isn’t a Mustang without a distinctive exhaust note. Thanks to plentiful choices from the aftermarket, you can customize the tone of your ‘Stang to suit your needs.
It’s easy to see that the free-flowing Roush mufflers carry less sound-deadening material. They are also physically smaller, which means your Mustang will lose a little weight in the process. Here, Power by the Hour’s Jake Long uses the new muffler to measure and mark where to cut the stock system.
Our friends at
Lethal Performance already made their 2015 Mustang more aggressive by installing a resonator delete. To further enhance the sound, they chose one of Roush Performance’s 2015 Roush Axle-Back exhaust systems (PN RSH-421834; $549.99).
We were on hand for the installation of this axle-back at
Power by the Hour in Boynton Beach, Florida. The system is a simple install, though it does require some cutting of the factory system to remove the stock mufflers. After that, it’s a clamp-on affair, and the results sound great when paired with the Lethal resonator delete.
Listen to a clip right here:
Built from T-304 stainless steel, the Roush system not only improves the sound of the car, but it might free up a couple extra ponies too. “Mandrel bending maintains a constant inner diameter with no kinks or creases,” says the company. “This improves exhaust flow and reduces backpressure in the system.”
Following the marker line he drew on the stock pipe, Jake cuts the stock exhaust pipe with a reciprocating saw. Whether you use power tools or a hacksaw, be sure to wear eye protection. You don’t want to get metal particles in your eye.
After cutting and remove the stock muffler, Jake slid the Roush clamp on, joined the new muffler to the stock pipe, and hooked the Roush muffler into the factory hanger. You can hand-tighten the clamp, but wait to final-tighten the 15mm bolt until you get the system adjusted.
With the muffler in place, Jake installed the exhaust tip. Having a clamp-on tip is a great feature of the Roush system, as you can fine-tune the alignment of the tip to the rear valance.
Once you get the system lined up the way you like it, you can torque the clamps to 22 lb-ft.
Likewise, once the 4-inch tip is matched up to the opening in the valance, you can torque the clamp to 22 lb-ft.
The process is exactly the same on the driver side. Mark the stock system using the Roush muffler as a template, cut the stock pipe, and remove the stock muffler.
Then hang the Roush muffler and clamp it to the stock pipe.
Install the tip, align it to the valance, and then you can torque the clamps to 22 lb-ft.
The finished system looks great and sounds even better, especially when paired with the Lethal Performance resonator delete. Make sure you have clearance for the wiring, hoses, and chassis, then you can test drive the car and make sure there are no leaks. Then you are ready to rumble.