Smokey Yunick said in his book "Power Secrets" and many others have said the same thing as it`s true. "The straighter the port, the better the flow"
This also rings true with any flow, this was the reason why the stub stack was developed for Holley carbs, it said "the air going in your carb is usually a turbulant mess, the stub stack aids airflow by straightning it" This was also the intention of the velocity stack air cleaners also. If we could get air to always flow perfectly straight into our engines there`s no telling how much more power we could make, but air`s not like that, anytime it hits a obsticle or a bump, it makes it creates turbulance. I`ve read where some don`t recommend a polish job in the ports or the intake and why was because: "You want to aid in the air/fuel mixture mixing properly, this is where turbulance helps, especially with nitrous oxide" and my thoughts are, true if your engine has no quench, but if your engine does have a tight quench distance, anything under .060, it`ll be fine, as this is what quench is for, to create turbulance to help the mixture be more combustible, to make it more efficent. So you`ll want to create turbulance in the cylinder, not in the intake or heads, but I highly doubt if anyone can polish one so well there won`t be turbulance, there`s too many curves, while we certainly can reduce it, we`ll never eliminate it completely. These gimmicks are telling us to do just the opposite. I remember the tornado when they first started advertising it on TV, and the guy had the 2 bottles together, and when he would make the water spin it would go into the other bottle alot faster than straight, and that`s because water is a solid, air is a gas, and the air mass is much greater than the fuel in the air fuel mixture. water also doesn`t turbulate as easy as air due to it`s weight. air is weightless, so it`s easy to turbulate.