Help Me Understand TIming Corrections? (Bm3 Logs)

[darkvader0]

[Can I post links to BM3 logs for public viewing? Does it work that?]
Bootmod3 Log

This is Bm3 Stage1 E30 I'm running. Am I looking at the "(RAM) Ignition Timing Corr (Total)" for the information I want? Or better the individual cylinders (which vary quite a bit and makes me curious why). I'm seeing -6.5 degrees total correction at times. Is it actually detecting bad sounds and reacting? Or does the timing correction also factor in things like IAT to arrive at the total correction preemptively?

I'm also looking at STFT/LTFT to verify my Ethanol blend. I see 0.85 STFT corrections under load and unless I'm reading it backwards, I think it's telling me it's pulling fuel--meaning too much 93/not enough E85. I don't have a tester to verify what's in my tank, but I have been calculating out E32ish on each fill-up. And I CAN verify that our fav. local E85 station always has E85-E89 even. It's only been two tanks or so of this, so I'm probably still building up the Ethanol blend in my tank, but still....any input? Maybe it's just a conservative map set to run richer by default, and pull STFT to optimum...?

Any insight welcome!

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[razorlab]

Most of that is IAT ignition correction.

Your IAT's start at 115F in 2nd gear and are 140F by the end of 4th. The DME will be pulling timing aggressively at those temps.

The stock turbo pumps out a lot of heat at those boost levels.

You really need to test your ethanol as well. If you do the mix right, first tank should be spot on, it doesn't take multiple tanks to "build up"

Here are the IAT correction tables. The top table is a based on IAT and Coolant temp and sets a percentage lookup of the bottom table. So at around 140ish IAT and 205 coolant, it is at about 70% of the bottom table, so at 200 load at 5500 rpm, it is taking out about 5-7 degrees of ignition. The OTS map might have softened this a little so you are seeing a little less being taken out.

 

[darkvader0]

Thanks, this helped me tremendously. So the IAT/ECT table IS factored in beforehand. It's July/August in Texas so I'm dealing with 102*F ambient.

Like you, I've been a long time tuner, and working to understand this for myself. I just got FEMTO unlocked a week or so ago so it's still all very new to me. Your other topic has been a great help.

Next for me is a flex-fuel sensor, but I wanted to try the manual mixing method first. Oh I meant that I had to estimate the fuel left in my tank when I first converted to an E-blend. And now that I pour 3 gallons of E85 to 8 gallons of E10 93 it will take a full tank or two to "build" a consistent blend.

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