JIC Exhaust Manifold increase your exhaust flow to the turbo, decreasing turbo spool up time and increasing horsepower. Each JIC Exhaust Manifold system features larger, smoother piping and minimal bends and high quality welds. All JIC Exhaust Manifolds are given a high quality polish to have that show quality look. Applications may differ depending on vehicle. Piping sizes can range from 38mm to 42.7mm.