A while back, we conducted a course in Exhaust Anatomy 101 to provide a beginner’s look at aftermarket exhaust systems. Now that you’ve brushed up on the basics, we’ll show you what makes an aftermarket exhaust system such a popular upgrade and provide tips on how to choose the system that’s best for your vehicle. Exhaust Construction: Crush Bends vs. Mandrel Bends So what makes aftermarket exhaust systems one of the most popular performance upgrades among hot rodders? Like aftermarket headers, performance exhaust systems are built differently than their stock counterparts to reduce power-robbing restriction, promote exhaust scavenging, and ultimately free up more horsepower. The first difference between a stock and aftermarket exhaust is the diameter of the pipes. The diameter ranges available on aftermarket exhaust systems vary depending on the application. However, these systems typically come with larger diameter options to flow larger volumes of air. Again, the proper ...