I'm going with the good silicone connectors from Road Race Engineering, my charge pipe is 2.5" but they don't have a 2.75" > 2.5" reducer, they have 3" > 2.5", would that be too big, what is everyone else using? Thanks

This is on a stock throttle body 99 civic si

 

use 2.5" for the TB side..it'll fit perfectly

stan

 

Yep the 2.5" coupler works, it is a tight fit on the Tbody but it does work.