Try a Go Tech 6 port .25. It is the best of both worlds, it has more torque than a .21 and better fuel economy than a .28.
http://video.google.ca/videoplay?doc...47493384507285
Here are a couple of video of a Go Tech 7 port turbo .21
http://www.youtube.com/watch?v=GHbWY...eature=related
http://www.youtube.com/watch?v=C21dY...eature=related