Ideally, you would want laminar airflow (this means no turbulence at all) to go straight into the cylinder. This would mean a polished surface with very few and slight bends, but considering the intake manifold, this is impossible. As for the vortex inducing TBS, I have yet to see one that really works, but at least the he helix ones (I have one on because I could not find one without it) do not block the flow of air as the tornado ones do...