Borla 12-14 Dodge Charger/Chrysler 300 SRT-8 6.4L V8 AT RWD ATAK Exhaust (Rear Section Only)Installation REQUIRES Cutting Original (O. E.) Equipment Exhaust System. This 3" diameter BORLA Axle Back system features the aggressive ATAK sound level. ATAK, Acoustically Tuned Applied Kinetics, technology 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. Even though the sound on the exterior is uncompromising, there is no resonance inside