Factory exhaust systems are designed to minimize noise. They restrict the flow of exhaust gases and create backpressure that steals power. If you're looking for better performance, consider aftermarket exhaust pipe kits. Aftermarket X-pipes or H-pipes allow smoother exhaust flow for a more efficient engine. An X-pipe, shaped like an X, allows exhaust to flow down the path of least resistance, producing more power than the restrictive factory system. An H-pipe is shaped like an H. A small section of tubing between the main pipes provides an area for gases to expand, which results in improved performance. To raise the performance level of a vehicle with a turbocharger, an after-market downpipe can offer significant improvement.