poormxdad

Gents,
Here's a log from a track session at VIR this past weekend and my current tune. In MegaLogVeiwer if you go to Max Boost of 9.7, it should take you to about 980 seconds. EGO is at 102.8%, but she's already 0.5 richer than the target AFR. If you scroll left or right, there are more examples of the same. VE Analyze indicates my fuel table is really close to perfect in the upper right quadrant, erring a bit on the rich side.
Any ideas as to why EGO would add more fuel than needed would be greatly appreciated.

Thanks much,

Spaceman Spiff

I'm sure deezums will have some strong opinions on the matter/MS firmware, but my solution to well implemented short/ (but especially) long term fuel trim was selling my MS3 and buying a Haltech Elite (which, if you're OK buying used, ended up being $100 cheaper than the MS3Pro PnP I had).

Reverant

iTrader: (10)

Your PID parameters are not setup correctly to correct fast enough. See below how a fast reacting PID should look like. See how it always try to be on the target and is essentially only thrown off during shifting.

poormxdad

Rev,
Thanks for chiming in. The P I D values were tuned on spirited jaunts around my town with some highway driving thrown in. It really doesn't mirror what happens on track, so it doesn't surprise me they need work. Now that I'm trailering the car, I will need to do a better job at those values. I have P=15, I=35, and D=5. Care to offer a hint at what I should try on my next track day?

After scrolling back and forth through the track logs, I also noticed EGO wasn't correcting fast enough. On the AFR/EGO Control menu, I have "EGO Delay After Fuel/Spark Cuts" set at 2 secs. Could that be a contributing factor? Interestingly, on the Over-Run Fuel Cut menu, I have "Delay EGO After Fuel Returns" set to 1 sec. I hadn't noticed that before. Which one takes precedent? All my ORFC settings may need to be reworked.

I'm envisioning rev-matching, downshifting, and engine braking before turns such that EGO starts to correct, gets locked in by "EGO Delay After Fuel/Spark Cuts", then reactivates at that locked in number in a very different part of the fuel table. If the rpms drop down through the peak around the 5300 rpm column, then EGO would be trying to provide much more fuel than needed, Does that make sense to anyone?

Thanks,

Reverant

iTrader: (10)

You will also want to decrease the ignition events per step. I have 4 instead of the standard 16.

poormxdad

I've been drinking and thinking... maybe I'm asking the wrong question.
My tune is a combination of tweaking the upper right quadrant based on track logs, but everything else is there because I have been driving her to and from events since 2011. I have a trailer now. Rather than fiddlefuck with the EGO P I D or the EGO Delay times, do I even need ORFC for a dedicated track car? Would I be better off changing when ORFC starts from 1.7 secs to 4 or 5 seconds, or more?
Thanks,

poormxdad

I've spent some time looking at the log. This Authority Table was a mistake.



The idea seemed sound (and it wasn't my idea)--I don't want the car to go lean on track and with the separate tables I could add a **** ton of fuel if necessary, but also have it set up to not pull much fuel. Unfortunately, those bottom rows seemed to be causing all my troubles. So I did this.



I was at VIR Monday-Tuesday and logged the changes. The new attached log shows when the engine goes into ORFC, EGO goes to 100% rather than getting stuck at some ridiculous number. Also, before the change there were only nine times where EGO was pulling fuel, even though the AFRs were consistently rich. The new table has EGO working pretty well.
I also noticed there were several times where she would go into overrun for literally 0.01 seconds. I changed ORFC to start after a 2.0 second delay from a 1.7 second delay. That reduced the number of short duration overruns. The Trubokitty '99-00 base map uses a 3.0 second delay.
I changed EGO to Only Correct Above 11.8 since that is the richest AFR Target in my table. It was originally set to 10.8. That, too, was a mistake. I plan to use something less than 10.8.
It was hot as ***** at the track, and I found my VE Table was not as perfect as I had thought. I will make some table changes, and adjust the MAT Air Temp Correction to pull a little fuel above 110 degrees.
If you are interested in a head scratcher, scroll to 1400 seconds in the first log. At VIR, for HPDEs they throw the checkers after the Oak Tree turn. I accelerate to about 100mph which puts me halfway up the hill on the back straight, then I put her into Neutral and idle all the way to the paddock. EGO goes to 85. Why?
Thanks,

poormxdad

Here's the new log.

poormxdad

Here's an interesting tidbit... I changed the numbers defining the Y axis for the EGO Authority Table (to make two rows of Zero correction at the bottom), but I didn't even look at the Negative EGO Authority Table. The defining Negative Y Axis numbers changed also to match, but there was no interpolation of the values in the table itself. Seems an odd way to implement it...

Ted75zcar

iTrader: (2)

post to the MSextra tunerstudio forums. Phil is a total rock star and will fix this right quick.

poormxdad

For this log I added one more percent to the Negative EGO table in the upper right quadrant, I changed EGO to use 4 Ignition Events Per Step down from 16 as Reverant suggested, and I changed EGO Delay After Fuel/Spark Cut to 1 second from 2.
It was even warmer in the afternoon. I do need to remove some fuel from the VE Table. I also plan to try delaying ORFC a little longer. I need to make the bottom rows of the Negative EGO Table all Zeroes. Unfortunately, my next planned track event is not for several weeks.