A buddy bought an s13 clip and this intake was sitting in the interior. It seems like a honda intake tube to me, and the diameter of it is pretty damn big. I'm guessing it's off of some jdm honda since this place just imports motors. Here are the pics:

http://www.norcalcrx.org/spoon2/pics/intake1.jpg
http://www.norcalcrx.org/spoon2/pics/intake2.jpg
http://www.norcalcrx.org/spoon2/pics/intake3.jpg

Thanks, -sean

 

i would guess ITR by the diameter of it

mike

 

The I.D. of the throttle body end of it is just under 3" if that helps at all. I don't know the specs of b series that well.