Originally Posted by BMW-M-Mexico
I have modified my ECU already and my local BMW dealer contact confirmed it is undetectable. What I got is a rev limiter increase to conform with higher quality fuel etc... top speed delimited, timing changed, etc... etc... together with the exhuast and ram air intake the dyno yield was 38 more hp and tad more in torque. Whatever the case, the car does feel leaner and faster.
One more thing I thought of.....
the ram air intake may yield you a bit on the dyno, but it should really shine at speed....when it is actually providing a ram effect! Too bad we can't get "in the field" measurements to see what the ram air does when "working" at speed. That would be cool. I bet when you are at speed, your HP increase is more than 38.