Dont know if anybody has done this on an rb25de . I now have most of the parts to make up a 2 x tb and 2 x afm setup . just waiting on a s/h manifold to arrive . Am going to cut off the side off the plenum where the single TB is , then weld on a 12 mm plate and mount the 2 x TBs on it . Then install seperate tubes to each of the AFMs . Electrically hooking up thru the apexi safc 2 which has provision for 2 x AFMs then converts signals back to a single feed signal to the ecu . Will keep you posted on progress .
presently i,m running a 68 mm tb , and its on a rb30de .