iirc, h&r's website says 1.3" front and 1.2" rear. since the stock sport suspension is 0.6" lower than the standard suspension, you're suppose to minus 0.6" from what h&r has said.
that said, i found that my 325i with sport package really dropped ~1.5" in the front and ~0.6" in the rear. you can find my findings in the suspension survey thread at
http://www.e90post.com/forums/showthread.php?t=21202