Exhaust manifold intended for: HONDA CIVIC 1988-00 B-series 4-1 Inner diameter of the outlet: 60mm Exhaust manifold by TurboWorks, made of 100% stainless steel. Guaranteed increase in power up to 10% When performing engine tuning, the exhaust manifold should be replaced already at the very beginning, because the exhaust gases extruded from the cylinder go to the exhaust manifold, which is part of the engine body, then they are directed to the first section of the exhaust pipe, then to the muffler, or several silencers arranged in series and then to the outlet part of the exhaust pipe. & nbsp