Originally Posted by poldim
Dont have time to read, has any E90 done it?
yes, I have and I've got nothing but good things to say about the results. Smoother response, better pull throughout the RPM range, etc. plus it's free.
One benefit I'm happiest about is the smoother response and the lags I noticed in the past have disappeared for now. To me that is the bigger gain then the possible increase in HP. The engines horsepower is only as good as the car's ability to deliver it. It's seems to be delivered much smoother now.