Originally Posted by Thomas@GIAC
For the 1M, Stage 2 only requires an upgraded intake and intercooler. We found that the factory downpipes aren't as restrictive as they are on the other N54 equipped cars. We do have a Stage 2 file for those wishing to utilize upgraded downpipes, but it is not a requirement for this Stage.
Berk Technology and Evolution Racewerks both run water-methanol injection on their 135i's. They are running our Stage 2 file, with the optional "Race" file (for 100 octane or 91/93 with 50/50 water-methanol injection).
This is interesting; so when you analyzed the exhaust for the 1M you came up with the conclusion that the downpipes are different and less restrictive than other N54 applications. Can you further comment, to what extend they are less restrictive? Is it still advisable to upgrade to let's say AR 1M down pipes or maybe it is not very cost effective because of minimal gains? I am not only talking about as a requirement for the tune.