Two Brothers Racing 2-into-1 exhaust systems are designed to deliver maximum torque. They feature race-inspired stainless steel headers that shave pounds off the competition to ensure a long lasting, weather-resistant, amazing sounding exhaust. From the engine, the exhaust flows through our 1 3/4" stainless tubing which includes O2 bungs to accommodate both stock and 18mm sensors. From here the exhaust steps up to 1 7/8" before dumping into the spring retained collector for increased torque. The exhaust then emerges from the collector into a 4" diameter muffler to deliver an unparalleled sound upon exit. Generation II exhausts feature classic megaphone style mufflers with a welded-on reverse cone.