So, I just upgraded to a B20 and picked up a few performance parts for it, namely a skunk2 Intake mani and 70mm throttle body. My friend claims that the throttle bosy will reduce my throttle response, but that doesn't sound right. Can anyone confirm if I'll be better using the 70mm TB, or will I get better throttle response with the stock 60mm?

 

Should also add that it's being used with an AEM long tube intake.

 

I don't think it will reduce response. That is big for just a B20, but I believe the intake manifold comes with a 64mm opening. I would just run the skunk stuff and call it good. If you get a higher flowing head or upgrade to forced induction later you might consider having the IM matched up with the TB.