Independent testing by Fall Line gave us the below results:
http://www.m3post.com/forums/showthread.php?t=232766
The testing was performed on a brand new M3, owned by Fall Line and destined to be stripped to a Grand Am race car. The car was fresh from the show room floor. Fall Line dyno tested the car that morning, installed the Eisenmann, and then dyno tested it again a few hours later in identical conditions.