29-09-2018, 08:27 PM
Like everybody else I slavishly followed the Willaims book years ago and removed the "obstruction." But is it? Or a transition to the small diameter of the manifold? has anyone done a before and after with no other changes? Some tuning books favour an inlet manifold with apertures smaller than the in the block. Curiously a homemade manifold just over 1 inch id seemed no better on my car but perhaps needle was not optimum.