Originally Posted by AK650
Will look for your results with great interest! I very much would like to put a cat less set of headers on my bike, and dyno tune it, but I'm being a chicken, and will not make any radical changes until my warranty expires. Theoretically, the Magnusson-Moss Act should cover blatant warrantee refusals, should something go wrong, unrelated to my tinkering; but it would suck to have the motor crap the bed, and have BMW say "too bad, your fault". For now, I will monitor via GS911, and possibly a WB AFR gauge, and try to learn a few things.
Good luck on the dyno tune session; hope it works out well for you. Also, a big thanks for sharing the info, I know from experience that it does not come cheaply!
I was hesitant first as well, but the poor performance with the motor trailside made me jump. That along with a good tuner/friend. Unfortunately he had little experience with the BMSK, and we were both clueless regarding the DJ 8GS APP shortcomings. During my testing since this was installed, I did learn a lot though.
One..... I would never put headers+ open pipe without some form of enrichment, simply too lean.
Two..... I would not invest in the DJ/AT combo with stock exhaust system. I would be worried with perhaps plugging of the CAT chasing power.
Normally I would think the Magnusson-Moss act would stand, but I think that the DJ install would be an easy way for the manufacture to wash their hands, as you are tinkering with the motor heavily. I think there now are enough evidence, not just in this thread, that there are clear cut benefits to a small enrichment to the 8GS, and safe to do so.