Corsa C5 Sport Axle-back Exhaust System - Black | 1997-2004 Chevy Corvette (14111BLK)Axle back System fits C5 including Z06 Models Straight through 2. 5", nonrestrictive system design maximizes airflow, improving performance and fuel economy. Mandrel Bends and design deliver airflow increases up to 47% vs. Stock Average increase of up to 10HP and 11 ft lbs. of torque CORSA's Patented RSC?? Technology allows us to acoustically style the sound of your Corvette to give you the true voice of performance without the annoying drone while