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Old 08-14-2016, 09:06 PM   #547
solidONE
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Quote:
Originally Posted by Tor View Post
Doh yes of course it would be OL. What a brain fart. Thanks.

So rather its rich in CL, hence the negative trim. Which is then applied in OL causing it to be lean? Would that be the right way to think of it?
I'd say yes. I'm sure there is a little bit more to it than that, but that is the basic jist of it.

I went ahead and took a log similar to yours for your reference.

Here's what the fuel trims look like on my car at part throttle in 5th gear. You will see it in CL operation under 4200rpms that STFT still active as Kodename47 was saying, then switches to OL operation once it revs past 4200rpms.

http://datazap.me/u/solidone/z7-olcl...0-352&mark=273

You'll notice that at the point where "fuel system status" switches from 2 to 4, the MAF voltage is around 2.8v. This is the area where you want to try to get your fuel trims as minimal as possible (as steve99 and wayno aluded to earlier). Keeping this area as accurate as possible in terms of fuel trims will help keep the fuel trims in OL operation nice and low. Now, this is probably a simplified explination of how the computer determins how much LTFT is applied in OL, but its a effective way to go about keeping the LTFT's stable in OL.

Here's a WOT pull to redline in 4th gear in the same log: http://datazap.me/u/solidone/z7-olcl...2078&mark=1879

If you look at my "commanded AFR" relative to the "AFR" it follows eachother fairly closely with "AFR" being a few points richer than "Commanded AFR" through almost the eintire way to redline. This tells me that my MAF scale is relatively "accurate" and actual AFR's are very close to what is being targeted in my OL fuel map.

I'm not sure whether you set your OL fueling table to run as rich as 10.5:1 (10.8 commanded AFR), or there is something off with how your logging device is set up. From the shape of your MAF voltages in your log im sure its a stg 1 or 2 NA setup but your OL fuel target past 6200rpm looks to be way rich for some reason, which is why I'm questioning your set up and tune.

http://datazap.me/u/tor/stock-a00g-m...2671-2776-2802
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