how big would you go with a throttle body with turbo?

 

well one thing that i know is that when you increase your throttle body size you decrease your air flow velocity, but you can flow more air in a given time. for example in turbo magazine they put a 100mm throttle body on a supra and from the dynos it lost a consistant 20 hp and 20 ftpds of torque, but gained 76 hp in the top end, and 50ftpds of torque in the top end. keep in mind this was on a turbp supra puting out 700 hp

i know thats an extreme example but it shows you that due to decreased air velocity you are going to notice some loses in the low end. this is why aem v2 intake goes from larger to smaller piping, they increase air velocity. im not sure how big i would go, i guess it depends on what boost leveles you plan on running

do you really think that at the boost level you are runing that your throttle body is chocking your top end? think about that for a while. in most cases, i think a stock throttle body would be fine or even bore it out a couple mm