Steve, I know you told me that a customer intake manifold yielded great results. Do you have any pictures, dynos, ect. of this? I am looking for information on this topic and where I can get one made.
it's really hard to explain how to make one, it's pretty much trail and error. You will need to know what runner length works best on the engine, how much plenium for damper etc... if you do a search on one of the thread on the rx7club, you will find a manifold we made and it made 600rwhp@20psi on our mustang dyno (approx 640rwhp on dynojet)