Quote:
Originally Posted by msmiljanic
Agree - 93 AKI = 97.4 RON. So if Halim is targeting and testing on anything more than 97.4 RON than the map would be too aggressive for US 93 fuels. We need to make some assumptions, so I will assume that Shell 93 is 93 AKI based on a reputable company and a seller that isn't purposely diluting or mixing to improve profit margins due to controls. I think the main questions I am trying to sort out are:
-how does Halim target a specific octane? Is it science? is it know how with testing? Or asked another way, how precisely does the 93 map target 93 AKI fuel?
Naturally there is a second question
-Does using an overly aggressive map for the fueled octane cause any damage?
The answer to these plus somebody's confidence in their fuel will tell them how to make decisions utilizing the various maps.
I have tested a couple times on the 5.5 map and I found one knock on one pull, and no knocks on others. I would have to do a lot of testing on stock, 91 map, and 93 maps to get enough data points to start making some kind of an assessment. It would be interesting to see if the stock gets knocks on 91. That would tell me BMW doesn't care if the knock sensors go off because they have systems to deal with it and thus they are not concerned about damage.
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Ok so, we look at different logging channels when we tune. Boost, timing, AFR and IAT are very important.
Octane affects timing, the higher the octane the higher ignition is possible resulting in higher power. We do not push the OTS maps to max, there is always a little room, why?
I've seen that the 93OCT can be good, but then you could have the perfect 93OCT but a very hot weather. There are too many variables that come into play, that's why we do NOT push the OTS maps to maximum. It's done in a way so it suits the majority of the cars, regardless if the octane is 92.7 or 93.x, hot or cold weather. Basically like OEM, just more power.