Intake manifold, what is this?

I bought a used intake manifold and noticed these flaps in the pipes:



The reason I bring this up is because the intake manifold in my Speed6 doesn’t have them. I can see the part which I assume rotates the flaps, and my Speed6 has that part.

So I’m assuming someone took out the flaps and the shaft they are attached to. Does anyone know why? Is this a common modification?

 

The flaps act to change the way the intake charge flows into the cylinder. Some people remove them to increase top end airflow. Possibly someone might have done some cleanup or gasket matching in conjunction with VTCS removal. Its not a magic secret to power production in most cases.

 

Thanks Synthetic. The car does apparently have an AP TIG gasket, could that be the reason? Would I need to be concerned about replacing the intake manifold with this one with the flaps if I’m reusing the AP gasket?

 

AP gasket works with stock IM and gasket matched ones you're fine as long as the gasket itself is still in good shape.