Originally Posted by BMW-M-Mexico
I've done my chip, did it with a guy recomended by the dealership that confirmed it is undetectable by the technition (don't really care of it is detectable though). Cost $2 grand!! The dyno with ram air intake, chip mod and exhaust showed 42bhp gain and similar increase in torque. Whatever the case, the car certainly feels faster right from the get go and wow when you get above 8,000 RPM. Among the things done were increased fuel, increasined timing, increased rev limiter (in accordance with local fuel specs) and, of course, delimited in terms of speed.
Can you post your dyno chart? Which company's tune did you end up going with? 42bhp sounds too good to be true!