New Tuning Tutorial: WeathermanShawn

[joecar]

Yes please, if anyone has found anything that needs fixing, please post.

[RevGTO]

Update: I did a base run, adjusted my VE & MAF tables, and then did a number of logs with the altered tune. My results so far show a fair amount of variability between the logs. For example LTFTBENs vary from the 1.00xxx range to the 0.97xxx range for the same hz category from log to log.

I had been using a downloaded VE table from Holdencrazy from a car with very similar mods. The VE results have been consistent enough for me to have established my own baseline B0101, with generally lower VE% numbers than downloaded table I was running.

Fuel trims have stayed close to what they were in my previous tune, but vary some from log to log. One was nearly ideal in the the -3 to +0.8 range, with the exception of numbers as high as +4 at 0%TPS in decel. My car has always tended to trim upon decel for some reason. I should say that my previous tune was developed when I ran OLMAF for a year; I continually adjusted my MAF calibration to get my actual fueling in line with commanded. Thus my MAF/VE combo was fairly close resulting in decent fuel trims even before factoring in the CALC VE results.

I'm going to take some more logs with my freshly edited Main VE table. If those results continue to fall within range, then another LTFTBEN adjustment should get it squared away.

My only issue is PE. My results so far indicate it is off. But it is hard to do extended runs at WOT on local streets and highways. I'm not going to be able to get a good indicator there until we have some decent weekend weather and I get the car to the strip.

[WeathermanShawn]

RevGTO:

Thanks for the report.

It was very informative. Believe it or not that swing in LTFTBEN's is not that uncommon. Weather changes, fuel type, even your fuel level can sometimes alter the Trims.

But, it is important to get consistency. And it sounds like you have. Your right, probably by run 3 you can be dialed in.

Trims on Decel. Always an interesting topic. So many of these Trims get locked in early on the learning curve. Just depends on your year of vehicle and what Fuel Trim Cell (FTC) you are in. Sometimes Decel gets it own unique FTC, and once its hard to budge some of the Trims in those cells.

More worrisome is PE. This method relies on the narrowbands and its relationship with LTFTBENS. Obviously PE ignores the narrowband feedback and requires a little more finesse to get it right. Suffice to say, if you can enter PE Mode with 0+ Trims, then you just need to look at the % difference between Commanded and Actual AFR (BENS) and adjust the MAF Freq accordingly.

Perhaps at some point the Tutorial can link to 'Methods of WOT Turing'..as it does require a some different approach. The challenge in writing a Tutorial was not only where to begin, but where to stop. Hopefully in the future we can figure out a way to combine Idle and WOT Tuning into a series of Tutorials.

Thanks for the feedback. Hope you can get your WOT Tuning done. Its only 10% of the VE Table, but arguably the 10% that is the most fun !

[TunasTwins]

We've got two documented trials now. Lets keep them coming guys! I'll get more data next Tuesday or Wednesday.

[RevGTO]

Believe it or not that swing in LTFTBEN's is not that uncommon. Weather changes, fuel type, even your fuel level can sometimes alter the Trims.

You're so right. I took one of my logs after putting some gas in the car, and the results went wildly off ... LTFT's in the -12-13 range. MAF readings too. I dropped that log when I factored in my results.

One thing that I've learned from this approach to tuning is that there is a certain statistical margin of error in logging that cannot be overcome. That probably has to do with the fact that all the factors in the system cannot not fully accounted for.

As a result of this tuning approach, my VE table is undoubtedly closer than it's ever been. I've given my MAF tables another round of adjustments from LTFTBEN multipliers ... we'll see where that gets me when I log tomorrow. If my fuel trims are still overactive, then I know I can manually bump my MAF settings to where my LTFT's are close to ideal.

[WeathermanShawn]

Thanks RevGTO:

Looks like you and at several others have had been reasonably successful in following the Tutorial. We will 'polish' up some of the typo's and update the calc_pids.txt information shortly.

I think it was very perceptive of you to see the normal variances in tuning, and to know when you are within the tuning 'zone'. It is a good idea to manually tweak when logging and tuning has taken you as far as you can go.

Thanks to you and to the others who have helped..

[mr.prick]

After filling up your gas tank, the cold fuel will throw LTFTs off for awhile.
Wait until LTFTs settle down before making changes otherwise
any adjustments made will be exaggerated and need to be undone later.
LTFTs get highly negative after I fill up the tank.

[DrkPhx]

Need some help. I finally got the Calc VE table to work, however the displayed values in the map are wacked out (way too high). I looked at the pid display in the scan tool and noticed it wouldn't let me select % or VE and the displayed values in the Units column are g*k/kPa,%. Can someone take a look at the attached txt file and see what's wrong? TIA

[WeathermanShawn]

I noticed that was your sae_generic.txt file.

I think you want it as your calc_pids.txt file. Look under 'Tuning' after you add it (My documents..user configuration..).

I have attached Joecar's latest calc_pid.txt file..Just make sure the displacement takes..You may have to enter the amount in Liters..per the Tutorial..

Just make sure you have DYNAIRTMP & LTFTBENS, MAF (g/s)selected also.

That should do it..

[joecar]

DrkPhx,

Try the attached sae_generic.txt file (it has your 6.587L displacement)...

Be sure to use CALC.VE_Table a rather than CALC.VE.