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Old 01-21-2003, 10:43 AM   #49
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Join Date: Jul 2001
Chapter/Region: SWIC
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Originally posted by Jon [in CT]
Some other observations.
It appears the ECU ignores other sensors which folks here have speculated are an influence on timing advance:
Mass air flow (MAF) sensor
Throttle postion sensor
Intake air temperature (IAT) sensor

Anyone who has used an SAFC on a WRX while monitoring a Delta dash can clearly see that MAF input effects ignition advance. The more fuel is removed with the SAFC(less MAF input voltage at the ECU) the more advance ramps up. In cases where the fuel system is far overkill for the application and alot of negative fuel correction is needed on the SAFC Ignition advance can rise to the point that its to much and knock is induced. Greg (Turborex) as spent hours datalogging this behavior and can offer more insight.

I have yet to try this reset trick but will datalog with delta dash my advance curve before and after the reset/trick. It will be interesting to see the final results.

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.

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Last edited by AZScoobie; 01-21-2003 at 11:08 AM.
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