aFe 46-40114 BladeRunner Ported Ductile Iron Exhaust ManifoldsaFe 46 40114 BladeRunner Ported Ductile Iron Exhaust Manifolds Bolt on instant performance by upgrading your restrictive factory manifold with this BladeRunner ported manifold. Designed to outflow the stock manifold by 12% for improved throttle response, this BladeRunner manifold has both the inlet and the outlet ports machined for a smooth transition and optimal flow path. Constructed from heavy walled, ductile iron to resist warping and cracking,