Originally Posted by BMW Fanatic
Catless = problem solved
Catless is going to get him ~5 hp more versus his HFC he has now. Not worth the smell, extra expense, and failing smog.
OP, it is very possible that this dyno has a calibration that is just somewhat low. You are worried about a difference of 30 WHP which equates to 8-9% of the reading. It's not easy to imagine that kind of difference from a dyno. It may be out of calibration or maybe the calibration is slightly off.
Basically, without a baseline, we can't tell you whether you are seeing the expected gains from your parts because the dyno is a bit of an "unknown".