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Unread 11-01-2014, 01:29 AM   #81
Rich Z
Internet Sanitation Engineer
 
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Join Date: Mar 2006
Location: Crawfordville, FL
Posts: 15,125
Name : Rich Zuchowski
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I hooked up the wideband O2 sensor and took the car out to do some logging. I wanted to make sure that the changes I did with PE didn't throw the AFR off, making it too rich when PE kicked in.

Actually didn't seem to change a thing as far as AFR is concerned. There are some lean and rich spikes here and there, particularly going through the gears from a dead stop, but nothing really drastic. Cruising the stock O2 sensors are only fluctuating around 5 percent or less, so that's not bad at all.

I may sharpen the slope for PE just a tad more in the 1500 to 2800 rpm range. I think that could use just a little bit more improvement. I just have to be careful I don't over do it. The PE table doesn't seem to care that 1800 rpm in second gear at 30 percent throttle doesn't have the same demands as 1800 rpm in sixth gear at 30 percent throttle. Haven't seen any bogging down yet, but I don't want to push this too far.

One thing I did notice since I was paying a lot of attention to throttle pressure while I was data logging. The throttle pedal is not linear as far as the PCM is concerned. Just barely touching the gas pedal puts it at around 7%. From 7% to 25% is just slightly more pressure. But it seems to widen out quite a bit at the top end when you get closer to 100% WOT. So you get a lot of throttle movement in relation to pedal pressure at the beginning, but it gets much softer up at the top.
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