No, you won't need a larger throttle body until you are very modded. And about the intake...What????? All intake create a whistle effect, supercharged or N/A. You hear the motor more. It is out IAC that makes a "shovel dragging on concrete sound" at idle. I'm still lost at what whistle your talking about. That is a supercharger that whistles. And you think making the throttle body BIGGER would get rid of the sound? Hardly. It makes it more pronounced IMO. As for the "bolt right in place with no modifications"...start another thread.