Flowmaster’s 30 Series Mufflers were developed during years of participation in the NMCA Fastest Street Car Series. As a result they the 30 Series is optimum for street performance. By using a combination of added volume and low-pressure balance chambers the removal of burnt gases from the combustion chamber is increased. An added benefit of scavenging is the cooling of your engine. The Flowmaster 30 Series produces a deep, powerful tone, with reduced exterior sound levels comparable to the 40 series, while delivering a unique sound of their own.