TEGIWA K-SWAP EXHAUST MANIFOLD FOR K20 EG EK DC2TEGIWA Race Exhaust Manifold. Changing the manifold is one of the best modifications you can do to your K swapped Honda. Just with this alone, gains of between 5 10bhp are achievable before mapping. With supporting mods and mapping, gains of between 7 15bhp and a lot more torque are easily achieved. Constructed from premium 304 grade stainless steel the header features the popular 4 2 1 design, CNC mill cut flanges, and robotic rotation purge TIG