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      02-24-2011, 04:21 PM   #51
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Drives: 2007 335i, 2015 M3
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Originally Posted by Morpheus View Post
Good post. Were the subarus you mention closed loop all of the time? Because if not, then you can't compare the two. I know the rx7s weren't, and you had to rely on user maps. These types of piggybacks would never have worked on an rx7. Just like the S-afc would not work-safely, that is. Maybe that's the reason for the confusion here?

It's also the reason you can't just slap on DPs an exhaust, and an intake and make 50hp with no tune. With an rx7 there was the 3 mod rule. Ever heard of that? Three airflow mods: intake, exhaust, downpipe. Any more than that and BOOM. Actually sometimes not, and sometimes even with less than three the engine went boom anyway. All it took was a hot day, or a bad tank of gas. Why? Because the ECU wasn't able to react. That's not the case here.

You're also incorrect in saying that the knock sensor is setting the BASE timing map. BMW sets the base ignition map and it does indeed look similar to the one you posted and does decrease timinq with load. I may be oversimplifying things here and somebody correct me If I'm wrong because I'm only repeating what I've read here, but it's my understanding that the flashes rely on the knock sensor as well, but with a 3 degree "head start".
Most of these guys have a hard time getting their heads around closed loop timing which as far as I can tell is exclusive to the N54 platform. It's a complete game changer. This thread belongs on a Subaru forum somewhere.