by Flannelman » Fri Jan 17, 2014 8:00 pm
Overall, a bigger port AND intake manifold looses low RPM torque due to air speed.
However, a larger port being fed by a smaller manifold will yield improvements from the air speed from the smaller manifold. From the head to the valve is the most restrictive part of the intake track so using a larger port the restriction is reduced. This in turn demands more airflow creating greater airspeed in the manifold.
It has been tested on a Ford V8. A 351C 4V had back to back dyno runs using a different manifold, one that mirrors this exact same situation. The larger stock manifold made 382Hp@6000 and a smaller Edelbrock RPM Air Gap manifold punched out 397@6000. Not only was peak power up, the torque curve was too. The Air Gap made more (391lb/ft V 400lb/ft @ 4000) AND held it over a longer rev range.
So, with the theory and the practical shown, I would expect the 3SGTE to improve in the mid range flowing into the top end with no noticeable loss in the lower rpm by using the small manifold on the bigger port head. WIN
The Flannel, formally known as Affroman