From what I understand both wheels keep rotation instead of the inside wheel "slipping" in the diff transfering power to the outside wheel. Something like this helps on the track (not the strip), but you will hear a gear whine during "normal" street or daily driving. Check out this you tube video: <[ www.youtube.com/watch? ] v=p1hEmGwBBtg&eurl=http://www.az350z.com/forum/viewtopic.php? t=10228>