Since posting this morning I got to thinking about my reference to manifold pressure as it relates to air volume passing through the intake. I inadvertantly stated that the Stillen kit and GTM kit should be producing the same HP/TQ at the same manifold pressures. However, I forgot that Stillen is using their own intake manifold and GTM is using Nissans OEM manifold. This may explain why the GTM kit is making more HP/TQ at the same manifold pressure. It's entirely possible that when going from the prototype manifold to the manufactured manifold something changed and the manifolds supplied are more restictive than the stock manifold. Therefore, the manifold pressure of the Stillen manifold would reach 8 psi with less airflow passing through it than the Stock manifold. Less air volume less power.
Anyone want to test this theory by removing their manifold and then porting and polishing it as much as possible and then reinstall and see the what the results are?
