These look like standard mufflers with a VERY unusual side entry rear exit configuration. Notice the heat discoloration at the intersection where the split occurs.Heat discoloration shows up where there is a flow restriction. Notice also the heat discoloration just after the pipes enter the silencers. It is AMAZING the engine makes the power it does through this congestion. Features Only 10 lbs [catless and non resonated version] 304 stainless steel piping Smooth air flow for maximum horsepower Compatible with both manual and automatic transmissions TIG welded to perfection... The main functions of exhaust systems are increasing horsepower and improving your engine sound.

By running pipes from the catalytic converter to the muffler and from the muffler to the exhaust tip, cat back exhaust systems improve exhaust gas flow, providing small performance boosts. However, your performance gains may be limited if your catalytic converter restricts gas flow, as a catback exhaust system is installed ‘downstream’ of the converter. Header-back systems are increasingly rare, namely because of modern emissions systems. Since removing your vehicle’s factory emissions components is highly illegal, the previous two options are more common. However, header-back systems are still available for some older, pre-emissions applications. In these cases, header-back systems offer more performance and volume than cat-back or axle-back systems