View Full Version : Fighting AFR, VE, MAF etc..Look over please
tatasta
March 26th, 2010, 09:46 AM
I had my car running well on the stock fuel pump and new 33lb. injctors then, I installed a Racetronix pump that I could not get the fuel pressure regulated below 72psi (without installing an aftermarket regulator).
So, I went back to a stock pump. I would just like anyone who has some time to look over the attached log and tune and comment on what you see, good or bad.
Thank you very much
mr.prick
March 26th, 2010, 11:18 AM
For the most part AFR is on the lean side in this log, about 3%
tatasta
March 26th, 2010, 01:29 PM
For the most part AFR is on the lean side in this log, about 3%
I have another iteration of this tune where I brought the MAF values in a bit closer to the logged data. Would you think that is wise or is tweaking the VE a better bet?
mr.prick
March 26th, 2010, 01:53 PM
With that .tun setup for MAF only, your only choice is to make changes to the MAF table.
joecar
March 26th, 2010, 01:54 PM
I have another iteration of this tune where I brought the MAF values in a bit closer to the logged data. Would you think that is wise or is tweaking the VE a better bet?Hi Robert,
Have a look at this: http://forum.efilive.com/showthread.php?t=13152
(the heading for the MAF map column should say "Value" not "value")
Use the equations from this calc_pids.txt (http://forum.efilive.com/attachment.php?attachmentid=7406&d=1269214633)
You can use either VE[%] or VE[VE] whichever you're currently displaying B0101 as... ([VE] is shorthand for [g*K/kPa]).
Read the tutorial pdf and give it a try and see by how much % it changes your MAF and VE tables...
This method is very easy and quick.
tatasta
March 28th, 2010, 07:01 AM
Hi Robert,
Have a look at this: http://forum.efilive.com/showthread.php?t=13152
(the heading for the MAF map column should say "Value" not "value")
Use the equations from this calc_pids.txt (http://forum.efilive.com/attachment.php?attachmentid=7406&d=1269214633)
You can use either VE[%] or VE[VE] whichever you're currently displaying B0101 as... ([VE] is shorthand for [g*K/kPa]).
Read the tutorial pdf and give it a try and see by how much % it changes your MAF and VE tables...
This method is very easy and quick.
Thank you Joecar. I was pretty good at this last year but, too much time has passed to remember the stuff you helped me with before.
Thanks again!
joecar
March 28th, 2010, 09:21 AM
No worries... this stuff is difficult to get mind wrapped around.
tatasta
April 2nd, 2010, 04:59 AM
joecar and WeathermanShawn,
I have everything setup for the tune changes and logging/maps according to the new tutorial. The only question that I have before I go log some data is; Previously, my tune had the LTFTs disabled. I have them enabled now but, will I disable them again once I get dialed in?
Also, is this mode CLMAF or more SD?
Thanks
WeathermanShawn
April 2nd, 2010, 08:12 AM
joecar and WeathermanShawn,
I have everything setup for the tune changes and logging/maps according to the new tutorial. The only question that I have before I go log some data is; Previously, my tune had the LTFTs disabled. I have them enabled now but, will I disable them again once I get dialed in?
Also, is this mode CLMAF or more SD?
Thanks
Once you are dialed in LTFT's are optional. I prefer to keep my enabled..weather, altitude, type of gas all alters stoich from time to time. But it is optional.
When you are running with MAF enabled, it is been my experience that a lot of the PCM function (Trims etc.,) are controlled by the MAF. Proving it has not been easy, but spark and also Trims appear to follow the MAF. I like to think of it as close to a hybrid MAF/SD tune you can get. There is an airflow correction that occurs when MAF Airflow and the VE Table are both being utilized. This method attempts to minimize that airflow correction..or to model the VE Table and MAF Airflow to compliment each other and provide a very stable and usable airflow model.
For the record the CALC.VE Table Formula was designed to give an accurate calculation with the MAF Failed..I.E. The VE Table Values are 100% dynamically derived (using MAF Airflow). Edit..MAF Failed, but Freq (HZ) and g/s Logged..In many case it is comparable to using a wideband to map out an VE Table. It just relies on the MAF Airflow to compute it. So, an accurate MAF Calibration Table is very important.
Hope I did not 'over-explain'. I think I can do this now in my sleep..:grin:
joecar
April 2nd, 2010, 03:31 PM
joecar and WeathermanShawn,
I have everything setup for the tune changes and logging/maps according to the new tutorial. The only question that I have before I go log some data is; Previously, my tune had the LTFTs disabled. I have them enabled now but, will I disable them again once I get dialed in?
Also, is this mode CLMAF or more SD?
ThanksHi Robert,
In your previous tune (I don't remember what you had):
- if you had LTFT's disabled, then that would be OL,
- if you had the MAF disabled, then that would be SD,
- if you had both disabled, then that would be OLSD.
- if you had neither disabled, then that would be CLMAF,
i.e. you can have (OL or CL) and (SD or MAF) giving you one of 4 combinations:
- OLSD
- OLMAF
- CLSD
- CLMAF
Watchout: with the COS if B3647 has any cells equal to B3601, the those cells will use STFT's to trim to stoich during OL (this is called semi-open loop, SOL).
So if you want to do Weatherman's tutorial, you have to enable both CL and MAF, then do the tutorial, and then if you want you can go back to OL and/or SD.
tatasta
April 3rd, 2010, 02:16 AM
joecar and WeathermanShawn,
Thanks for taking the time to spell alot of this out fir me. I was going to take a run this morning and log some data but, once again, it snowed sideways last night...you know April showers makes May snowmen...here in the tundra.
Maybe it will clear off this afternoon.
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