[autoteach]

Originally Posted by ShadeTreeMech

As much as I respect the knowledge of those technical enough to argue on such a higher plane of thought, I would have liked to have seen this stay at a more laymans level, which I believe most of us are.

Knowing this argument was likely ongoing nearly made me decide to delete this thread from my subscriptions list.

I wonder what improvements in efficiency a variably tuned intake manifold could show? Basically, the length of the runners from the boxy part of the intake manifold to the valves helps dictate the power band. When an intake valve shuts there is a reflection of energy back into the intake which, when it bounces off the boxier part of the manifold, reflects back to the valves. If the timing is correct, and the reflection hits the valves when they are opened, more air is forced into the valves and gives a boost in power. Suppose the intake runners were longer, and there was a movable blockage that would adjust to take the best advantage of tuned ports by lengthening the runners at low rpms and shorter at higher rpms.

Is such a thing possible? I know there are some variable manifolds that adjust according to engine demands, but could something like this help with economy?

This is better. Variable length intake manifold - Wikipedia, the free encyclopedia

Could something like this be adapted to cars that don't already have it?

pretty sure that your wife is sitting on it. 4DSC.com : Articles