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The VE table is :wtf: with this turbo. I understand conceptually that I should be adding more VE in the boost areas, but touching this table in any big way (like a block of cells scaled 20%) has made LTFTs go crazy in the past -- but crazy in a totally upredictable way -- B1 went more positive, B0 went more negative from the looks of it. Where values were like -2.3 and -3.9 before, they were -1.6 and -5.5 after in the same FTC :crazy: . I quickly pulled the stock table back out and have stayed the heck away since then.

 

I'd love it if one of you s/c guys could tell me what changes were made to your SSS VE tables.

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Do LTFT's lock at 0 while your in WOT?

 

When you hit open loop mode, there are no LTFT or STFT readings at all. The PCM does use the last value (or 0 if you LTFTs are negative when you enter PE mode).

 

Looking at my latest logs, I am seeing LTFTs of 0 in both banks for FTC 15 at 90-99% throttle (I rarely actually see 100% tps). Since I've adjusted my PE enable down and PE enable vs tps, I think that's why -- they were never 0 before those changes.

 

In the scanner, the LTFTs go to zero in graph and table modes, but in the gauge mode, stop registering readings at all (and the readout defaults to zero which is the case I think- software artifact because the PCM is not sending a signal anymore)

Edited by TurbochargedBerserker
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Do LTFT's lock at 0 while your in WOT?

 

When you hit open loop mode, there are no LTFT or STFT readings at all. The PCM does use the last value (or 0 if you LTFTs are negative when you enter PE mode).

 

Looking at my latest logs, I am seeing LTFTs of 0 in both banks for FTC 15 at 90-99% throttle (I rarely actually see 100% tps). Since I've adjusted my PE enable down and PE enable vs tps, I think that's why -- they were never 0 before those changes.

 

In the scanner, the LTFTs go to zero in graph and table modes, but in the gauge mode, stop registering readings at all (and the readout defaults to zero which is the case I think- software artifact because the PCM is not sending a signal anymore)

People with EFI Live are used to seeing LTFT's lock at 0 during WOT if you are rich (0 or neg) in the LTFT cell before WOT was initiated. A positive value during WOT, means you were lean, and thus the PCM calculates a given amount of fuel added as you enter WOT. This leads to irregular fueling during WOT, and hinders tuning PE @ WOT. This last part, I'm sure you understand by now. This was my point as you asked about lean conditions @ WOT.

 

Goodluck :cheers:

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And these are the days of our KR lives...

 

I backed down on the PE settings and manipulated the curve a bit. Here's why... The PCM has a nice little AFR spark add... the bounderies are at .05 (so 1.20 1.25 1.30 ... The 1.30 setting adds sooooooo much spark (+7?? I think) that a getting anywhere close to 1.3 adds KR...

 

I could have adjusted that table directly, but the truck just felt better at 1.27x at redline. So... now at 1.278 at 4.8k - 6k and 1.272 for 3.4k to 4.4k.

 

O2s look much more stable (but I haven't parsed the data yet, just all the averages I pull (tps >83, >90, >98 : my PE comes on at 83) are all 890+ and within 3 points of each other (that seems pretty good to me).

 

I have reduced the KR to one specific range and one specific set of precursors. Basically, if I am between cruising at 50 - 62 mph, and floor it causing a downshift, I get KR. From watching the scanner, I know I am about 30-31.5 advanced when I floor it and am about 0.60-0.66 in g/cyl. I've also noticed that I can get KR without flooring it in these situations (I can go to 60% tps or so and get some bad KR with no boost). I *believe* this is the old downshift KR bug, but am going to go the VE table at those RPMs and air readings and boost the transient range. Dunno what effect that will have on my tune, so the back up plan is to reduce the timing from the cells I am coming from.

 

Almost down with low boost tuning...

 

High boost is delayed to do a back order :cry:

 

No numbers yet (haven't even been logging calculated torque) but the "pull away" and "seat of the pants" dynos show good results.

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I have my "AFR timing add" set to zero. Makes it easier to tune WOT fueling. This table was not used (i.e. set to zero) in earlier year PCMs. The Radix tune also has this table zeroed out (when stock tune was not zero).

 

Another tip: what is your KR decay set at? In Edit, the stock values are around 60. I currently have mine set at 500. Having the KR go away over 8 times faster is nice. :D

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Thanks Deezel. Trying both of those suggestions on the next tunes.

 

I've finally had luck tuning the VE table -- and it did solve part of the tip in KR problem.

 

I've noticed some really weird stuff changing the timing tables. If I test them immediately after uploading, I am almost guaranteed to get tip in KR in first downshifts. If I wait 10-15 minutes as Ben suggested above, no tip in at all.

 

:confused: I though the timing changes wouldn't require relearns... There must be some AF calculation somewhere that is requires a small adjustment period.

 

Everyone keep your fingers crossed... Trying some agressive timing today -- nice wide, flat timing curve under boost.

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  • 3 weeks later...

I'm pretty much there. I still have some transient KR, but not much. I am playing with the VE table trying to get everything "perfect".

 

I've also adjusted my o2 rich/lean values since the last update (now slightly rich globally) and moved to a less aggressive VE table from where I was. Timing is "done" and WOT will be done very soon (wink wink)

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I have my "AFR timing add" set to zero. Makes it easier to tune WOT fueling. This table was not used (i.e. set to zero) in earlier year PCMs. The Radix tune also has this table zeroed out (when stock tune was not zero).

 

Another tip: what is your KR decay set at? In Edit, the stock values are around 60. I currently have mine set at 500. Having the KR go away over 8 times faster is nice. :D

where do you set the KR decay value??? I see where it says Knock Retard Decay it in the Spark Retard tab, but there is nothing to adjust. it's blank.

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so what did you end up leaving your PE delay and Enable MAP at?? what did you think helped the most with Tip In?? did you leave your VE tables alone?? I've read this post a lot of times and am not sure on your overall process.

 

thanks!

 

I'm having some of the same Tip In and general knock problems...

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My PE delay is 2600 and the enable MAP is 45. The enrichment rate worked at .043, but I am experimenting with 1.00. I think the enrichment rate was the most effective tip in treatment. The closer to 1.00 you get the faster you get to full PE.

 

I also increased the burst kr delta cyl air.

 

I have recently had some luck with the VE table (I decreased my IFR and boosted the VE to help level the LTFTs closer to 0 .. -2 (had some that were -6 .. -8 and while that works, it seemed to be a rougher tune than what I've got now). The VE table seems most responsive in the 2-3 cells closest to the axes (so 400 800 1200) or the first three kpas. It seems to be least responsive farthest away (which is FTC 15 and generally is open loop mode at that point anyway). My next step is a small MAF adjustment if the VE can't 'normalize' the LTFTs.

 

What I'm doing now is past the tip in stuff and is just 'smoothness tuning'. I am having some down-shifting KR, but have been able to isolate it from tip in and it is responding to timing table adjustments.

 

Let me know what's up and if I had a similar problem I can tell you what worked for me.

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