Why don't you guys lighten up? Explain the reason behind the mod then tell why it doen't help until a certain point, then how it helps. Not just repeting the same garbage. This is a new club, not the i-Club, the only thing your post is missing is "do a search", shutting down mods with no reasons is frankly for people who do not know what they are talking about, and just relaying garbage that they read someplace else. I doubt that you are those kind of people, so kick it up a notch.
I don't believe that the TB being bored in and of itself is that great of a mod either. Like I said most places do more than simply bore the TB and put a bigger throttle butterfly in place. You can do the same mods yourself, but not make the TB bore anybigger and raise the effeciency of your engine in the process. It will not put a kick in your pants when you do it, but all the little mods that "don't do anything" when added together are what makes a good engine package.
Calculate how much air is going through your TB by taking your engine displacement and finding how fast the air is traveling through it. By reducing the turbulance of the throttle plate in the middle of the TB opening, by making the cross section smaller, and the "lip" of the TB a smooth transition from the attached pipe into the TB, airflow will be smoother and more efficient. Think velocity stack, smooth airflow, fluid airflow.
Don't expect to gain alot of HP from the mod. Remember your engine is a system, with all the parts working together, increasing the effeciency of the parts of the system that you can without alot of trouble, will all add up.