I'm looking at putting the fwi on and I was wondering, is it possible to just leave the rubber part that comes attached to the throttle body on and just use this rather than buying the elbow and coupler? it looked like the inside diameter was 3.5" or something, at least that was what the diameter of the air box going into it was. So could I just run some pvc pipe into this rubber part and forget about messing with the couplers?