KR elimination

[Foghorn]

Can anyone tell me what other tables affect the timing under WOT?

Commanded Timing = (Good Fuel Spark + IAT Spark + ECT Spark + AFR Spark) - (KR + TM)

If the High and Low Octane Spark tables are the same then the calculation should be straight forward.

Cheers,

[PDXGTP]

Two questions...when does the PCM choose between the High Octane or the Low Octane timing tables?

The PCM will use the high octane table until it gets a certain number of KR & degree of hits on the knock sensors. Then it will drop down to the low octane table.

I'm seeing very low timing (5, 6, and 7's instead of the 10, 11, and 12's that the high octane table is set for) at WOT in PE. I've already zero'd out the PE adder vs. RPM vs. time. Can anyone tell me what other tables affect the timing under WOT?

PE adder vs. RPM vs. time. shouldn't effect timing at all.
IAT's will, its in the Engine/Spark Control/Spark Advance Spark Correction. That is the only field that should be populated with negitive numbers.
If your commanding 10* of timing and seeing 3* of KR... = that makes sense to me that you would be seeing 7* of advance. minus what is being pulled be your IAT's if they apply.
Torque management will also pull timing but you stated that you have adjusted that out.
Please post your file so I can have a look at it.

[99ssei]

Ok, so I just realized a scanning boo boo I made. I was trying to change the PIDs (add/remove) and had some troubles with the histograms not capturing certain data, so I inadvertently used an old config that was not capturing MAF in Hz, commanded AFR nor the TCC Duty %. Gotta go back in and add those.

I'm in the middle of adjusting the MAF +7000 hz. I put the IFR @ 100 kPa back to stock (38.4) and started massaging the MAF. The IFR was 10% lower from stock, so I used the same % to raise the MAF above 7000 starting at 1%, 2, 3, 4, 5, 6, 7, 8, 9 and 10% all the way to the end. In the first scan below is right after the 1st engine cycle - key off, so you can see the trims being learned, but the end of the scan should be good data.

http://www.scandepot.net/viewscan.php?pk=5470
http://www.scandepot.net/viewscan.php?pk=5471

The next scan is a compilation of three scans put together. I think I have a bad cable because randomly, my cable would become "disconnected." I saved the scan, disconnected, re-connected and picked up scanning as soon as I could (while rolling). You'll see this in the frames and time, however, there's maybe a 30 second loss of data between each.
I don't know how to post my bin here, but here's a pic of my timing tables mentioned above. The highest I seen my O2s in all scans were 933.

http://www.scandepot.net/viewscan.php?pk=5473

[99ssei]

I added back the missing parameters (and then some) and drove around a bit late last night. I was very impressed with the performance! KR didn't get over 1.8 and I had plenty of WOT data in this scan. However, this morning, she was back to the usual 2-3 KR (which is better than when I first started seeing 6-9 KR). We're getting closer!

http://www.scandepot.net/viewscan.php?pk=5476

[PDXGTP]

Just thought i'd ask... what gas station do you go to?
Some brands are better for KR elimination. I noticed that the Shell station in Corvallis has some good clean gas. those 2~3* blips in Bob's car went away completely when he went to that station, then later he wwent to Chevron and they came back.
Check it out, you might be able to locate a station that gives you the goods..

[99ssei]

Just thought i'd ask... what gas station do you go to?
Some brands are better for KR elimination. I noticed that the Shell station in Corvallis has some good clean gas. those 2~3* blips in Bob's car went away completely when he went to that station, then later he wwent to Chevron and they came back.
Check it out, you might be able to locate a station that gives you the goods..

I think 99% of gas stations around here have 10% ethanol added. I typically go to BP, but have always had good performance with Shell. Problem is Shell is usually 4 or 5 cents more. Today I had to go with Citgo. Btw, I always put in 93.

[99ssei]

The PCM will use the high octane table until it gets a certain number of KR & degree of hits on the knock sensors. Then it will drop down to the low octane table.

What is the certain # of KR & degree? Is there a calculated value?

[PDXGTP]

The PCM will use the high octane table until it gets a certain number of KR & degree of hits on the knock sensors. Then it will drop down to the low octane table.

What is the certain # of KR & degree? Is there a calculated value?

Great question.. I haven't figured that one out yet. .
You really causing trouble now. see.. now I have to figure it out.. Please stand by..
I have a feeling that we can't see it because its hard coded.. at least not at this time. HP tuners is pretty good at getting us stuff that's useful but some things just aren't available.
I'll ask HP Tuners if they can at least tell me/us.

[99ssei]

Made some adjustments to the 7000+hz range and looks like the O2s are coming into their own (Seeing them hit 933).
We changed the High Octane spark table up to 12 deg. at 3200 rpm and up for last three columns in an effort to increase the timing.
We also made some adjustments to the Acceleration Enrich vs. TPS Maximum Delta and Acceleration Enrich Modifier vs. Speed table. This morning's scan is looking better. Still seeing some 1's and 2's, so we'll probably still be adjusting the AE stuff. I know I've already tested this before, but I"m going to copy the high octane spark to the low octane spark. I'm commanding 12 degrees, however, I"m only seeing 5, 6 and 7. I gotta figure out how to get more timing.


http://www.scandepot.net/viewscan.php?pk=5481

[Dirthead Racing]

I know this sounds backwards but instead of copying your gst to your bst, take some timing out of your gst where you are only seeing 5,6,7 deg of timing and see what happens. I had a similar issue and had to take some timing out to keep it from dropping into the bst. I would set it to 10 for a trial and see if it gives you any more timing. I just noticed that this is a 99, is your mbst set to 5,6,7,8 deg timing by any chance?

[99ssei]

I know this sounds backwards but instead of copying your gst to your bst, take some timing out of your gst where you are only seeing 5,6,7 deg of timing and see what happens. I had a similar issue and had to take some timing out to keep it from dropping into the bst. I would set it to 10 for a trial and see if it gives you any more timing. I just noticed that this is a 99, is your mbst set to 5,6,7,8 deg timing by any chance?

I'm assuming mbst = Mean Best Spark Table? Where do I find that in HPT?

[PDXGTP]

That must be some of that DHP lingo.

[Dirthead Racing]

That must be some of that DHP lingo.

Yep, maybe it's not used with HPT. I don't have it with my 97 pcm so I don't know much about it other than the tuner guides telling a person to make sure to adjust it correctly. Nothing to see here folks

[99ssei]

Hmm....I need to read this tonight. Just saw the over view and thought it might be pertinent to what we're trying to do here.
http://wiki.opentuner3800.com/index.php ... ing_Tables

[99ssei]

Progress is being made!! Tonight's scan is looking much better! For the exception of the end of my scan, which was me logging how the car reacts when I floor it from a stand still (the 4, 5 and 6's), all other WOT KR is down to only 1's and 2's. My LTFTs are 0, my O2's are averaging 933-934, but my timing is still in the 7-9 range. Going to read that document on timing now.




http://www.scandepot.net/viewscan.php?pk=5490

EDIT: After reviewing the play...I've decided to take out 1 degree of timing in the .92 g/cyl @ 2800 & 3200 RPM cells. Also going to try re-gapping my 104s to .055.



EDIT 2: While pulling plug # 5, I noticed the metal bracket with a hole just above #5 (think it's used to pull the motor) was a bit loose. Only one bolt was holding it in place, so I decided to just remove it. After removing the bracket, I noticed the nuts holding the manifold on around # 5 were not tight. I went around the rest of the header bolts checking to see if all were tight and found the ones around #6 were also not tight. I tightened them up real good and I'm hoping this was the teeny tiny exhaust leak I was hearing from the #6 area.

[99ssei]

Had a flat tire this morning. Scan data is same from yesterday. Even with a degree pulled out of the trouble spot, still seeing same amount of KR (scratching head wondering why). 02's were a tad low, so I just added 1% @ 7000 and up. Here's the scan data:
http://www.scandepot.net/viewscan.php?pk=5493

Do I keep pulling timing out until it's gone? Or should I be looking at other things?

[Dirthead Racing]

Whether it's right or wrong, I've been pulling 1 deg in the rpm cell during, before and after. It seemed to clear up my KR. Not the most efficient but I've found it effective.

Also, don't forget to look at the big picture. You're not going to pop a piston with 1 deg of KR at 3600rpm. You can scan stock vehicles that run for 200K+ miles and they will have more KR than that. I can scan on tuesday, have 0 KR through everything, thursday I have 1 deg KR, friday, no KR. I didn't change a thing. My $.02

[99ssei]

Much better results tonight! Not seeing more than 1* of KR! I made a change to the AE max delta (basically smoothed out the graph so it looks like a curve). O2's are good, however, I have to adjust the MAF slightly.
Side note, it was almost 70 degrees while scanning and this weekend will probably be the last 70 degree weather in our area until May.




AE Curve


Scan
http://www.scandepot.net/viewscan.php?pk=5494

[PDXGTP]

I would rather have the slightest little blips of KR then none at all because you know that you are as close as possible to your max available timing. total optimization..
especially in the WOT timing fields used.
Once you throw a few drops of race fuel in it... all clear. :thumbup.

[Dirthead Racing]

I was thinking the same thing