New Tuning Tutorial: WeathermanShawn

[picnic_george]

Can you post the E40 .tun file.

Here ya be..

[RevGTO]

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 somewhat different approach. The challenge in writing a Tutorial was not only where to begin, but where to stop.

I am bringing this back up from an old post for anybody who might be reading this thread contemplating a Calc VE tune. It's an important bit of info toward completing the tune. Since there is no narrowband feeback in PE mode, those LTFTBENs will show up as 1.000. As Shawn says, one has to manually adjust the appropriate MAFFREQ cells by the differential between commanded and logged AFR's to get PE fueling on target. It took me a couple of trips to the track and a few adventurous freeway runs to get my PE in line doing this.

[WeathermanShawn]

RevGTO:

It is an excellent point. I am very glad you brought it up. I will try to clarify.

In a MAF-Enabled Closed-Loop tune there will a certain MAF Frequency known as the 'PE MAF Crossover Frequency (Hz) or MCF. Depending on your PE TPS & RPM settings, all MAF Frequencies above the 'MCF' will no longer be in closed-loop. In fact they will be in Open-Loop as defined by the PCM.

The short summary is that that portion of the MAF Calibration Table will need to be tuned using the general techniques of the AUTOVE method. This utilizes a wideband and the use of AFRBEN's. It is the only method that will allow you to calibrate your Commanded AFR vs Actual AFR in PE Mode and WOT.

If you think about it, this method shares a lot of similarities with AUTOVE. It simply uses the narrowbands to solve the stoich (~14.63 AFR) closed-loop portion of the VE Table. Of course, its uniqueness is that it takes advantage of the PCM's reliance on MAF Airflow and Trims to determine a highly accurate and representative VE Table.

Could the CALC.VE Tutorial be expanded to cover this portion of tuning? Yes. I left this portion of the Tutorial purposely open, since wideband AFR tuning is well-documented. I knew a few more astute tuners and deep thinkers would understand the connection.

So, congrats RevGTO you have hit that designation. If you ever get a tune and log that you want to share, let us know.
Thanks for sharing..

[FeetDry]

I'm looking at the files in post 169. It appears the tutorial was last updated March 28.
Looking at the calc_pids.txt,...
It appears the displacement() has been replaced w/ 5.669. I'll guess this # is in Liters. True? (5.7L~= 350CuIn)
It wasn't clear to me if the call to displacement() was suppose to work. i.e. Is the call suppose to return a #? Where does this # come from, (PCM, EfiLive)? Is this suppose to work for all OS's, just specific ones? Is this suppose to work for only the latest version of EfiLive? (A manual entry will lead to errors down the road.)

What is the purpose of CALC.LTFT? I don't see it used in any of the other CALC PIDs. So, is it needed?

When there is no air temp PID, can I use DYNAIRTMP= 0.85*IAT+0.15*ECT for any OS? Or will this only work for LS1's? (This is just a best guess equation, right?)

[WeathermanShawn]

I'm looking at the files in post 169. It appears the tutorial was last updated March 28.

Yes. This was a Tutorial started from the efforts of 2-4 people (multiple contributors). We are logging errors and discrepancies. It makes more sense to make significant updates all at once, so please be patient.

Looking at the calc_pids.txt,...
It appears the displacement() has been replaced w/ 5.669. I'll guess this # is in Liters. True? (5.7L~= 350CuIn)

When this Tutorial was published there was still an unrelated software bug that affected any equations that included displacement. The figures are for a 5.7 Litre engine. By now, you should not have to manually insert the engine size..

It wasn't clear to me if the call to displacement() was suppose to work. i.e. Is the call suppose to return a #? Where does this # come from, (PCM, EfiLive)? Is this suppose to work for all OS's, just specific ones? Is this suppose to work for only the latest version of EfiLive? (A manual entry will lead to errors down the road.)

I believe it comes from the Scan Tool entry under Customer Details. I will check on your other inquiries.

What is the purpose of CALC.LTFT? I don't see it used in any of the other CALC PIDs. So, is it needed?

The method utilizes CALC.LTFTBENS. In closed-loop it takes the average of the LTFT Trims correction and applies them to the MAF Frequency. It is an essential tool to accurately calculate an equivalent VE Table for those running MAF-Closed Loop.

When there is no air temp PID, can I use DYNAIRTMP= 0.85*IAT+0.15*ECT for any OS? Or will this only work for LS1's? (This is just a best guess equation, right?)

There is a DYNAIRTMP.DMA Pid available for the LS1 PCM's. It is the heart of the method. Since the VE Table calculations utilize DYNAIRTMP it uniquely applies it to the corresponding MAF frequency/airflow. In its purest form, DYNAIRTMP is highly accurate. Other OS's without that PID must utilize a look-up table methodology, or use the 'best guess' equation referenced above.

Hope that helps..

WeathermanShawn..

[TunasTwins]

Hey guys, cant find dynairtemp on a buddies 99 vette PCM 9354896. What am I missing here?

[WeathermanShawn]

Hey guys, cant find dynairtemp on a buddies 99 vette PCM 9354896. What am I missing here?

On MY OS (12212156) it is found under 'Tune' on the Scan Tool...

[TunasTwins]

Well, its there- just not supported??

[WeathermanShawn]

Well, its there- just not supported??

A lot of times you just need to hook the Scan Tool up to the vehicle. using the Scan Tool..under Info..hit Validate Pids..

That usually does it for me. I am not the computer 'expert', so perhaps there is a newer and better way. The bottom line is that a number of 'Unsupported Pids' only become validated when you 'Key-on the Car'..with the Scan Tool connected.

Hope that does it for you.

[TunasTwins]

A lot of times you just need to hook the Scan Tool up to the vehicle. using the Scan Tool..under Info..hit Validate Pids..

That usually does it for me. I am not the computer 'expert', so perhaps there is a newer and better way. The bottom line is that a number of 'Unsupported Pids' only become validated when you 'Key-on the Car'..with the Scan Tool connected.

Hope that does it for you.

Thats what I did. It was the first time connecting to this vehicle so I had to validate PIDs but couldnt see dynairtmp. I'll have to try again