Normally Aspirated engines and Supercharged engines still rely on proper exhaust tuning to promote the optimal flow velocity of exhaust gasses leaving the exhaust ports. APR introduces a unique and proprietary X-pipe design that was developed through multiple reiterations to perfectly match the pulse of each cylinder in the 4.2L FSI V8 to provide optimal exhaust flow. Often times, exhaust manufacturers will incorporate X-pipes into all Normally Aspirated or Supercharged applications generically without realizing that the sizing and shape of the ports in the X-pipe require specific tuning to each engine application. APR's Engineering Team has discovered a trade secret exclusive to APR's RSC™ Exhaust System that promotes maximum velocity of exhaust gasses by way of the X-pipe to ensure your APR RSC™ Exhaust System will compliment your future modification choices at even the highest horsepower and torque possible.