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Old 01-21-2003, 12:04 PM   #54
Jon [in CT]
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Member#: 2992
Join Date: Nov 2000
Chapter/Region: NESIC
Location: Connecticut, USA
02 WRX Sedan


Originally posted by AZScoobie
Anyone who has used an SAFC on a WRX while monitoring a Delta dash can clearly see that MAF input effects ignition advance.
I found Shivs post interesting because I have been using this trick for about a year now without knowing what I was doing and or why it was working. I discovered this trick while drag racing. I noticed on a reset ECU my times would drop. This was back before the delta dash existed so I was guessing as to what was causing the power loss. While experimenting and pulling a few ideas of posters on this forum I found that reseting the ECU and then running wastegate boost on the way to the track before boosting up high would always net a faster time. Add race fuel, Reset ECU, Turn boost down to 8psi, Drive to track, turn boost up.... I posted that suggestion many times to drag racers on the forums. Now I know why it worked.
The low- and high-octane ignition tables may, indeed by indexed by "Load" and not MAP and "Load" may be based, in part, on MAF. I guess the point is that "Octane Learning Mode" is entered based on MAP, not MAF.

And I could only find one instance where you publicly recommended something along the lines of "Add race fuel, Reset ECU, Turn boost down to 8psi, Drive to track, turn boost up" and it was different in one very important aspect. The post I found was and you said there:

Reset ECU
Set boost low like 10psi
Drive 20 miles and 4 or 5 restarts
Toss in race fuel
Turn boost back up to 15-16 psi.

The significant difference, of course, is that you recommended adding the race fuel after the ECU had learned the octane of some other lower-octane fuel. But maybe that was a typo.
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Last edited by Jon [in CT]; 01-21-2003 at 12:09 PM.
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