Impreza EJ20 Exhaust Manifold

When relationship of inhalation and exhalation of air is tuned with the EJ20 engine, response power improves, but low the rotary limits become the big weak point. The part in order improves the part of that and to raise efficiency with total, is this exhaust manifold. Pipe layout and pipe diameter are considered, by the fact that 4 - 1 types and piping inside diameter 42 Φ are set in the gathering part, low revolution, low torque rise in the rotary low-speed limits is made possible, furthermore also the engine response in the middle rotary limits improves substantially. Riding easiness with the street of course is optimum to also the circuit and motor sport competition.