Tuning Notes by WeathermanShawn

[WeathermanShawn]

Mick, I understand what you are saying..The MAF (LTFT) calibrated airflow, almost perfectly matches the SD (via wideband) airflow? When I log each of the appropriate DMA Airflow Pids..they line up very accurately. And my assertion is that if you are maintaining stoich during non-PE throttle conditions, and your WOT matches your Commanded AFR. In an auto primarily utilizing a MAF and in closed-loop..one can construct a highly accurate VE Table by using the EFILive VE.CALC. Pid.

Bottom line..you do not have to do an AUTOVE, followed by a MAF vs AFR Calibration..if you run a MAF closed-loop tune. It is primarily a method for beginners. As beginners advance, they can delve into some of the other methods to perfect their tune.

[joecar]

I say let everyone who is interested try it out for themselves, and then report back.

[joecar]

...
Don't you guys use Closed-Loop? Does anybody use a MAF on this forum? Perhaps I am the lone user of EFILive that uses this method.
...

Shawn,

You're not wasting your time, don't be discouraged...

When Tycho Brahe and Johannes Kepler were trying to discover the mathematical equation(s)/model(s) of elliptical/orbital motion, they did not come up with the correct model until they spent many iterations of comparing each model with observed data... when a model disagreed they refined it or rewrote it and tried again...

Brahe maintained huge amounts of observed data but was never able to find the right model... Kepler did eventually find the right model using Brahe's detailed data (Kepler's Laws)... meanwhile in the background the authorities were enforcing the firmly established belief that the Earth was the center of the solar system (no equations provided)...

[voda1]

I say let everyone who is interested try it out for themselves, and then report back.

I agree. Sounds like a practical/efficient way to tune. Looking forward to trying your method come spring.

[tinindian]

Shawn - Whatever you come up with - I'm all in. Thanks for taking the time to help guys like me.

Mark

[tinindian]

Thanks Man. Unfortunately I live in Iowa so my car is tucked away for the winter. But I'm certainly looking forward to reading your material and tuning with it in a couple months.

[TunasTwins]

Thank you for taking the time to put this together. I believe your system accomplishes what you set it out for: to get new tuners headed in the RIGHT direction. Often, the initial gratification of tuning is stretched out over several years. Yeah there may be some inaccuracies in the process but the final output (real world) WORKS. Your method isnt scaling the crap out of just the MAF or the injector constant to hit the correct PE AFR. And for Marcin, thank you! We always have to challenge new theories (or old ones). Thats what science is! BOTTOM LINE: Lets try this out for ourselves and see if we like the results, then report back. Thanks again.

[mr.prick]

Shawn,
One note you might want to add is to change the display of {B0101} to % Of Theoretical Maximum.

[redhardsupra]

This post is riddled with inaccuracies, so let me address each point separately.

Well, I think the same temperature biases exist when you are doing an AUTOVE Tune. If your ECT and IAT fluctuate during your tune..you will be off. Try it over several days. The BEN(s) are different, especially as your IAT varies.

MAF is bias-free. Since MAF measures the final result (the airflow) and not its components (pressure, volume, temp), there is no problem with temp estimation or mesurement.

There is probably a mathematical way to take a log run and standardize the values to a 'standard' temperature.

yes, that's what solving for absolute values of GMVE (as opposed to all the prevalent 'adjustment' methods) that I've been talking about for the past 2yrs is all about. Proper attribution is NOT an option, it is the very base of science.

I think where the point is being missed..closed-loop 'solves' those IAT and air density differences. They Trim accordingly. I have taken a nearly perfect SD and MAF open-loop tunes from 5500-1200 feet. Neither one gave any where nearly perfect fueling . It was only when I re-enabled closed-loop that the car performed perfectly.

I guess closed-loop thinking is just not welcomed or accepted on this forum. Probably the majority have aggressive camming, or have FI or Turbo applications.

CL for tuning is not favoured anymore. If you look back to 2005, very few people had widebands, so they did the best they could with stockers. The first time I tuned my car, was with narrowbands on the street. It worked fairly well. I then rented a dyno and I improved another 6hp. So both methods can result in similar results, however, the street/CL tune took me 5 months, as opposed to the dyno which took me 3 hrs.
OL is much better for observing YOUR changes, not changes coming from all the modifiers (whether they're fuel cutoffs, traction control, cat protection, spark, fuel trims, idle air trims, etc...) this is again proper attribution: you want to know if what you changed had a desired effect, or was it just a result of coincidence or changing conditions. You cant do that in CL by the very definition of CL. I have another name for tuning with CL: letting the ECU doing its job.

Only now do I appreciate the difficulties involved in introducing a method that is not widely accepted. See, I think the really smart people on this forum either run SD or Custom OS's. But, in my area the terrain and weather conditions change rapidly. I prefer closed-loop, because it Trims perfectly as IAT and air density changes. But, it seems to be an a tuning method that lacks respect on this forum.

Of course such a tuning method does not command respect--you claim that you're improving the tune, while all you've done it let the ECU do its job by trimming. What is YOUR contribution? Where is the novelty?

Nothing personal fellow members, but I am leaning toward backing off on this project. Anybody that wants to run closed-loop knows how to do it. But, probably 40-50% of beginners have great difficulties in mapping a VE Table, doing the laborious MAF Calibration. Then if they prefer closed-loop, they find all the Trims are just as 'wacky' as before. I know, I spent 2 months on those first two steps, and then realized I was going in circles.

Mick, I think that all airflow models have temperature biases. I think the way around it is to log when IAT are steady, or filter out IAT's that vary during a log run.

All I was trying to share is that a MAF produced Airflow Model..using EFILive's CALC.VE Pid can easily be cut and pasted to your VE Table. If you apply your LTFT's correction to the MAF Calibration Table prior to the cut and paste..you will have a tune that gives perfectly stable stoich and Commanded WOT AFR's.

so your contribution is to take the MAF airflow and use it as the data source on the VE table, right?

I'm leaning toward just letting the Tutorials staying as they are. I have probably put out enough ideas in this thread to get people thinking. But, I am getting the idea that it is not being readily accepted.

People are always welcomed to view my tune, or PM me if they have questions. If closed-loop tuning is viewed as 'heresy', I certainly have other things to do with my time. Marcin and others have worked for years on this..and I have yet to see a published Tutorial that accomplishes anything. You can talk about theory for years. It takes courage to put your name and ideas into a real Tutorial.

Sorry for the 'rant'. Perhaps I am just a little exhausted right now.

Here is my proposal. If I am officially asked to put together a draft Tutorial, I will do it. Whether TAQuickness, Joecar, Mr. Prick, or yourself can then massage, polish, and decide if it is applicable to publish..I will still do it.

I guess I am still befuddled why there is so much push-back on this concept. Don't you guys use Closed-Loop? Does anybody use a MAF on this forum? Perhaps I am the lone user of EFILive that uses this method.

Guys and Gals..I just do want to waste my time on this project if there is no widespread applicability.

Not mad, just tired.

..WeathermanShawn..

I am still failing to see any novelty or benefit to your method. It's not any shorter because you still have to drive and scan and cover all the cells. It should actually take longer, because instead of taking precise measurements (WB), you're using broad lead/rich conditions (NB).
Have you at least made a custom pid that generates the new VE table for you, backcalculating the VE values from the MAF airflow?

not mad, just tired,
Marcin

[WeathermanShawn]

Marcin, as a scientist I believe you guilty of the following..you have a 'selective' reading flaw. You are not actually 'listening' to the words I have written. You are making conclusions that in some cases I have not made.

On the issue of maintaining tight control of IAT's during a run. You are missing my point. If you are sampling the same RPM/MAP data point with multiple IAT samples in a single log, you are just simply increasing the deviation of the CALC.VE %'s. Same principle whether doing SD, MAF otherwise. Try a log at 0C and one at 30C on the same log. You will just be increasing your data spread.

The benefit is exclusively for MAF-based auto's running closed-loop. You can still operate your vehicle any way you want. But, for this method you are having to do only one log run in order to produce a VE Table and MAF Airflow that matches and is accurate when operated in closed-loop. My wideband verifies it is accurate.

Marcin, the bottom line is that you are always welcomed to publish your own method on this site.