You really only need an after market LSD in supras.
here's a flash vid of the Efantis car in the 7s:
http://transwarp.supras.cc/efantis.swf
here's a picture-in-picture of the Titan Motorsports car in the 7s:
http://www.project240sx.com/TX2K6/TitanFastest.JPG
Boost Logic has run 8.11:
http://www.boostlogic.com/media.html