Originally Posted by Marki_GSA
Sorry but your statements are completely at odds with my own and many others experience as far as the 1200 GS is concerned. Yes they can compensate but not indefinitely and a free flowing air filter at sea level will definitely take it out of bounds. There is only so much extra fuel in the map bins and once your outside the boundary your into mixture problems. O2 sensors by the way only trim mixtures in a closed loop situation I.E cruising. Outside this area they have no affect at all as they are only lambda sensors and not wide band sensors.
As far as I know the BMW has a barometric pressure sensor (altitude) in the main comp unit, the O2 sensors, intake temp and pressure sensors as well as the knock suppression sensors and engine temp sensors to balance and accommodate the variables of operation. (As far as I know) Just my experience of course and I am not a BMW engineer or tech so do not have access to the actual figures and mapping comparisons - however my own experience on the track and the dyno with the BMW Cup bikes saw no change in the mixtures with various number of exhausts, cut and reformed air-boxes, and more than a few air filters including no filter at all. This was a few years ago. This involved many long hard hours in the shop and the only solution was getting access and clearance from BMW to use the BMW computer program to modify the mapping - they didn't want to do that of course.
My comments also come directly from a very good friend and racing buddy of mine who is the owner of a multi brand BMW dealership and his main BMW tech. As I posed the same questions in response to our experience with the 1200 on the track to them and my sometimes rough running bike after long hauls.
Maybe we didn't get outside of the parameters you talk about - perhaps - but with my own R1200GS "2006" I also saw no visible signs or change in spark plug colour with the addition of a K&N, OEM paper and now my oiled foam air filter - or my full cat-free Laser exhaust and headers. And that accounts for over 100k of mileage and many different filters and two exhausts - and approx 7 sets of plugs as I change them every year.
As the BMW paper air filter as tested and commented on this forum flows more air than an oiled K&N or even my oiled foam filter - I would think that would richen the bike and not lean it out - but again no change.
After all is said and done - I don't have specific data that I can show you to back any of my comments so they are just that. And, you know we could have screwed it all up too... you never know.
Take it for what you will.