Flat-Out Aggressive
Borla’s GT350 ATAK system delivers aggressive sound and more power
By Steve Turner
Photos courtesy of Borla Performance Industries
There is no doubt that the factory exhaust system on the latest Shelby GT350 sounds fantastic, especially with its adjustable valves opened. Combined with the unique sound of its Flat Plane Crankshaft-equipped Voodoo engine, this system sets a high bar for factory exhaust tone. However, those of us that love performance Mustangs always want a little bit more, which is where Borla enters the picture with its new Shelby GT350 exhaust system.
“The Borla Cat-Back Exhaust System for the GT350 features our patented ATAK Technology that is based on specifically tuned attributes of the internal muffler cores, which are calibrated on a vehicle-by-vehicle basis to deliver the most desirable sound,” Lisa Carter, Social Media & Marketing at Borla Performance Industries, explained. “A deep and aggressive sound, however, is not the only thing to be gained from our system.”
To give you an idea of what it sounds like, Borla put together this video…
[video=youtube;k8dk6JJ1w_U]https://www.youtube.com/watch?v=k8dk6JJ1w_U[/video]
Built from stainless steel, this system (PN 140684; $2,293.99) is built with a true X-pipe that maintains a 2.75-inch diameter tuning throughout. It is also designed for compatibility with both the factory air-cooled tips and electric valves. Not only the are its ATAK mufflers tuned for the Shelby, but the valves built into them are also much larger than the factory units to improve exhaust flow, which helped deliver a solid improvement in rear-wheel horsepower.
“Our system picked up 18 horsepower (at the wheels) and is 13.4 pounds lighter than the stock system,” she said. “In addition, our products are made from T-304 stainless steel, are very durable, are backed by our Million Mile Warranty, and are proudly made in the USA.”
This Cat-Back system is available now, but that’s not all Borla has in store for the Shelby GT350. In the near future the company will release a set of headers that add another gain of 12 horsepower for total system gain of 30 ponies.
If you own a new Shelby GT350 and you want a more aggressive exhaust system, Borla now offers its 2015-2016 Shelby GT350 ATAK Cat-Back Exhaust (PN 140684; $2,293.99). This system is a direct bolt-on and is compatible with the factory exhaust tips and electric valves.
It’s easy to see how the Borla system picks up some power as the stamped factory X-pipe (top) isn’t optimized for flow and its diameter is inconsistent. Meanwhile, the Borla system features an artfully constructed X-shaped crossover that is 2.75 inches throughout.
While Borla engineered the system with built-in valves designed to work with the factory electric motors its engineers decided to improve the flow in the mufflers by making the internal valves larger. As you can see the Borla valve (left) is much larger than the stock valve.
Here’s a look at how much bigger the Borla valves (bottom) are. They measure at 2.69 inches inside, while the stock valves only clock in at 2.22 inches.
Because of the improved muffler and larger valves, the Borla muffler outflows the stocker in both configurations, but with the valves open it does so handily. This is especially true at the top of the tach, where it beats the stockers by 88 cfm.
Thanks to the improved muffler design and the smooth 2.75-inch tubing, the complete Borla Cat-Back easily outflows the stock system. It does so from the jump, besting the stock cat-back by 124 cfm down low and pulling away by a whopping 235 cfm up high.
It features improvements in the diameter and straightness throughout the system to create impressive power gains and more aggressive sound, but the Borla system still bolts on right in place of the factory system.
