Vibrant 4 1 Stainless Merge Collectors Vibrant 4 into 1 SS Turbo Manifold Merge Collector for T4 Divided Flan S8998df2b222e4994a0e3980ad36830af3.jpg Performance Slip On Merge Collectors: 2 1 4" 2 into 1 2 1 Stainless SS Exhaust Merge Collector Dual 2" ID Inlet Single 2.5. Vibrant Performance has developed a comprehensive, high quality and Affordably priced range of 304 Stainless Steel Merge Collectors to help our customers free up maximum horsepower from their exhaust setup. For many years, merge collectors were almost exclusively used by top professional race teams. However, this proven technology is now commonly used at all levels of professional racing (where rules permit) and now many fabricators are incorporating merge collectors into street header applications.