I do agree about the baseline dyno test. As for AFRs, its not actually a straight line on my Mog tune, I certainly don't use straight line when setting up on aircraft, but then nor do they vary massively either.
I think, there is very roughly a 8-10 hp hike (say 10%) since the Stage three, but it may be less. This is based on what the dyno chart says and what they say a standard Mog kicks out. Seat of the pants estimate suggest broadly same.
Quantified against the cost, it might be well well worth it if you do a lot of two up / A road travel, assuming no problems manifest themselves with the upgrade..
Ben
