Your MAF sensor needs a laminar flow going past it to get an accurate reading. This is why we go with smooth intakes and gradual mandrel bends. Turbulence and swirling air is bad.
In the days of carbureted engines with maze-like passages in the intake manifold, this might have been of SLIGHT benefit, but not on a modern fuel-injected car. This will hurt performance and mileage by giving inaccurate MAF readings. Your MAF sensor will be reading less air than actually exists (and the tornado will also decrease the air delivered), causing your PCM to run lean, even though it thinks the AFR is correct.