Quote:
Originally Posted by Mrdjc
You need to bear in mind what the values actually represent, AFR - Air to Fuel Ratio.
Ideal Stoichiometric ratio is 14.7 (14.7 parts of air to 1 part of fuel)
The map is aiming for 12.5 in your example, which is 12.5 parts of air to 1 part of fuel. So it's not lean at all, its rich. 
As for the Advance timing, it depends on the quality of fuel available as to what it would have been set up for, if your only able to get the equivalent of 91RON in the US instead of the 101RON in Japan, there is a good reason for it being a whole lot more conservative being a USDM vehicle compared to a JDM or EUDM vehicle. |
I suppose I should clarify that I'm not new to tuning at all, just a little new to direct ECU modification based tuning. The other platform I've mainly worked with is 3000GTs and Stealths, where the only options are piggybacks or complete standalone ECUs. I'm just getting into the hex stuff.
I know ALL about air/fuel ratios. Coming from a forced-induction mindset of tuning, 11.5 is typically considered rich best torque, and is a good safe place to start tuning from. Leaning it out obviously makes more power, but at the increased risk of detonation. I don't usually see performance pump-gas tunes get much leaner than about 12.2-12.5, and that's the richest point on the SVX's stock map, so you can now see where I'm coming from saying 12.5 is "lean". 12.8-13.2 or so being the generally accepted best power AFR, but is usually far too prone to detonation unless very high octane fuel is used.
My comment was more aimed at the fact that Subaru went with the best power AFRs and used extremely conservative timing to control knock. It seems kind of backwards to me, as I'm used to seeing 12.0 AFRs and much more aggressive timing curves. I can't say which works better with these cars as I'm just getting started with this platform, but it seemed odd to me. With the other address file, I now have a "max advance" table though, which does make things look a bit better. I was originally under the impression that the base timing was the max advance and that there was just a knock retard table.
Like I said, I'm brand new to these ECUs and just trying to learn what I can. Thanks!