Confused by breakpoint calculated byEEC analyzer

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Confused by breakpoint calculated byEEC analyzer

Post by alollich » Thu Jul 25, 2019 7:13 pm


I ran a short log thru EEC analyzer checking on my slopes and breakpoint. I am using 24 lb ford injector and have Ford's provided data for the 24's entered in BE. My current slopes and BP are 24.6 hi slope and 26.7 low slope with a BP of 2.219. When I run the log in EEC analyzer I get a recommended high slope of 24.5 hi slope and 25.5 low slope with a BP of 8.4. I don't understand the suggested BP of 8.4?

The log is a 30 second average acceleration from a stop...not a WOT log or anything with a lot of load.

Engine is a 302,stock HO cam, Twisted Wedge heads, and a ported stock manifold.

Thank you for any help you can provide to help understand the 8.4 BP suggested by EEC analyzer.

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Re: Confused by breakpoint calculated byEEC analyzer

Post by jsa » Thu Jul 25, 2019 8:00 pm

Give it more data to work from, with plenty of steady state at various load points.


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Re: Confused by breakpoint calculated byEEC analyzer

Post by cgrey8 » Fri Jul 26, 2019 8:26 am

Keep in mind the Breakpoint is an indication of when to transition from low slope to high slope. And as the low and high slope get closer to the same value, the less relevant the breakpoint value becomes. The breakpoint is only critical when the high and low slopes are very different. With the values you are quoting, the breakpoint "almost" has no meaning.
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Re: Confused by breakpoint calculated byEEC analyzer...confused again

Post by alollich » Mon Jul 29, 2019 4:37 pm

Ok so I logged about a 15 minute drive with just about every type of driving possible. Slow starts, idle, moderate acceleration, WOT, and highway cruising. All logged in forced open loop with the adaptives turned off. I also have the majority of the fuel adders/multipliers set to one so that I am not influencing the data. The transients and enrichments are still there. After running the log thru EA the slopes and breakpoints made sense as to what it was suggested. Very little change actually. I ran it thru the maf function (chose open loop in the tool) and it spit out a rather significant adjustment to the curve. Three to five percent on the lower end and 11 percent of the upper end of the curve. I made the adjustments suggested and drove it again for 20 minutes. Ran the log thru EA and again the slopes didnt change much, but the maf curve that was suggested was again and increase three to five percent down low and 11 percent higher up. I made the changes disconnected the battery for 10 minutes and drove it again for 20 minutes. I ran the log and again slopes did not change much but the maf suggestion was again a couple percent low and another 10 percent up high. So at this point the truck is so fat everywhere that its a total pig to drive and darn near has raw fuel coming out the tailpipe.

When I started this today the tune/curve in the truck I felt was pretty good. My WOT was a bit off that I intended to adjust by lowering the low slope a bit and there were a few points thought out the curve that were slightly off based on my logged wideband afr and commanded lambse. I got to this tune by logging drives and then going back by hand and calculating the difference between wideband afr and commanded lambse and updating those points in the curve with percentage error. Almost impossible to hit every point by hand so that is why I decided to run it thru EA and see what it suggested.

The three passes thru EA suggested a total of 10 -12 percent increase down low in the curve and 30-304 percent higher up in the curve. What I was left with after making the suggested changes is my cruising afr is down in the 12s and my WOT afr is in the low 9s. Basically it runs like crap and drinks gas.

Any suggestions why EA continues to add fuel to a curve that is way fat? I there a problem with my method? Am I missing a setting in EA? My experience with binary editor and EA is that the suggested changes dont have the impact on the issue that is expected. I realize that EA is not the end all be all and you have to use your brain and make sense of what its telling you and adjust accordingly, but so far any suggestion EA has made has not improved the tune. Hence it make me wonder if I am missing something in the settings or its just user error.


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Re: Confused by breakpoint calculated byEEC analyzer

Post by Bossxr8 » Mon Jul 29, 2019 4:49 pm

I couldn't get EA to spit out a useable maf curve. Seems like it just doesn't work with the data provided. Maybe the data isn't what it requires somehow.

I just did my maf curve manually.
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