i have one of these xpipes on order. it should be at my house in about 1-2 weeks. i was planning on doing a before and after dyno just for kicks.
take a look at the notes at the bottom of the dyno chart. they did the baseline test in the morning (cooler) and the same car later in the day when it was much warmer and still made good power. i was impressed by that.
i got a great deal from redline360, send them a pm.
http://www.m3post.com/forums/showthread.php?t=1370895