S-AFC Question
Thread Starter
Joined: Mar 2002
Posts: 7,592
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From: Toronto, Corporate Canada
S-AFC Question
Little confused on what Hi and Low Throttle position feature to put Into the S-AFC. What are Its functions exactly? Is It a standard number? Some details would be great.
Former Rx7 *****
Joined: Nov 2001
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From: Mississauga
"They are used by the S-AFC to calculate fuel corrections at various TPS readings (throttle positions) at each RPM. At TPS settings below the Lo-Thrtl point, fuel corrections are constant - this is good for letting the ECU operate properly in closed-loop mode. At TPS settings above the Hi-Thrtl point, fuel corrections are also fixed - good for compensating for a throttle pedal that doesn't go as high as 100% (such as caused by thick carpeting or floormats). At TPS settings in-between the two, the S-AFC always calculates a correction proportional to the Lo-Thrtl and Hi-Thrtl numbers. Close to the Lo-Thrtl point, the correction will be more like the Lo setting at that RPM; while close to the Hi-Thrtl point, the correction will be more like the Hi setting at that RPM."
http://wac.addr.com/auto/obs/safc/safc.html
http://wac.addr.com/auto/obs/safc/safc.html
Thread Starter
Joined: Mar 2002
Posts: 7,592
Likes: 5
From: Toronto, Corporate Canada
Yea but couldn't the throttles be set on zero, for example. That way the S-AFC Is making fuel adjustments allthroughout the throttle position. By doing It this way you are maximizing (customizing) the piggyback to work according to what you Input at rather than having any fixed points?
Thread Starter
Joined: Mar 2002
Posts: 7,592
Likes: 5
From: Toronto, Corporate Canada
Originally posted by Aaron Cake
You have a S4, so set the low throttle to 93%, and high throttle to 94%.
You have a S4, so set the low throttle to 93%, and high throttle to 94%.
Joined: Feb 2001
Posts: 29,798
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From: London, Ontario, Canada
The TPS on the S4 is not full range...ie. 100% on the TPS is about 1/4 throttle. So you want to set the S-AFC so that anything less than 1/4 throttle is "low", and anything more is "high". It's not the best solution, but it's the only solution besides swapping in the 89+ TPS (annoying).
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Wow, that Subaru site is really good!
BTW, I don't recommend the "blue wire" mod - DSM'ers have proven that it can load the output of the O2 sensor a bit and cause false readings.
Dale
BTW, I don't recommend the "blue wire" mod - DSM'ers have proven that it can load the output of the O2 sensor a bit and cause false readings.
Dale
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