PDA

View Full Version : In Which MAP/RPM should the AFR will be less than 14.63 (stoic) ?



wesam
June 6th, 2010, 07:53 PM
I'm in the process of tuning my VE table i want to know MAP/RPM should the AFR will be less than 14.63 (stoic)
i know in the high MAP 90-105 it should be 12.8 max for N/A cars but what about the area 3500-4500 RPM in the 75-85 map ?? what is the ideal AFR for it ?

gmperformancecentre
June 6th, 2010, 10:33 PM
i'm using

14.05 75kpa 3600 - 4800
13.59 80kpa 3600 - 4800
13.00 85kpa 3600 - 4800

wesam
June 6th, 2010, 10:37 PM
i'm using

14.05 75kpa 3600 - 4800
13.59 80kpa 3600 - 4800
13.00 85kpa 3600 - 4800

Do you mean you try to reach those values using VE or those the commanded values ?
sorry for this question i'm new in this field

WeathermanShawn
June 6th, 2010, 11:03 PM
Do you mean you try to reach those values using VE or those the commanded values ?
sorry for this question i'm new in this field

Whats wrong with the Commanded AFR's in the AUTOVE Tutorial?..http://download.efilive.com/Tutorials/PDF/AutoVE Tuning Tutorial.pdf (http://download.efilive.com/Tutorials/PDF/AutoVE%20Tuning%20Tutorial.pdf)

gmperformancecentre
June 7th, 2010, 01:09 AM
commanded afr's
this is with EFILIVE'S OS5 Custom OS

voda1
June 7th, 2010, 02:43 AM
Wesam what operating system are you using for the tune?

wesam
June 7th, 2010, 02:59 AM
Operatin system 01250001
OS ID V1
Checksum $0E98

voda1
June 7th, 2010, 05:04 AM
Whats wrong with the Commanded AFR's in the AUTOVE Tutorial?..http://download.efilive.com/Tutorials/PDF/AutoVE Tuning Tutorial.pdf (http://download.efilive.com/Tutorials/PDF/AutoVE%20Tuning%20Tutorial.pdf)

If the ECM is using the richer of VE or CFOL - the problem is figuring exactly which table is providing the AFR. Does the VE BEN 'ONLY' pickup a value when the AFR is coming 'FROM' the VE table? If so, could one do a BEN map for CFOL table?

WeathermanShawn
June 7th, 2010, 05:27 AM
If the ECM is using the richer of VE or CFOL - the problem is figuring exactly which table is providing the AFR. Does the VE BEN 'ONLY' pickup a value when the AFR is coming 'FROM' the VE table? If so, could one do a BEN map for CFOL table?

The VE will give you the amount of airmass needed for a particular AFR/EQ. The 'CFOL' is simply a multiplier of that airmass.

I am sure someone can explain it better than I can. But, if you are solely following the AUTOVE Tutorial, you must successfully follow the instructions to map out your 'VE Table. That determines your airmass for that particular EQ. The CFOL is just an EQ multiplier to the VE Table. It 'looks' to the VE Table for the airmass and then applies the EQ multiplier you have chosen.

From Joecar:

Wideband reports the same AFR as commanded AFR if these are all true:
1. B4001 and injector tables are correct,
2. When PCM uses VE: B0101 is correct,
3. When/if PCM uses MAF: B5001 is correct,

PCM calculates airmass from:
- above B0120: MAF,
- below B0120: MAF (steady throttle/airflow) and/or VE (transient throttle/airflow),
- in SD (MAF-less): VE.

PCM determines AFR from:
- CL: closed loop feedback trimming to stoichiometric AFR (B3601),
- OL: the richer of: B3605, B3647 (COS), and B3618 (if PE has enabled from B3608-B3616).

The various protection mode AFR's are reflected in the commanded AFR.
The PCM selects the richest AFR from the AFR tables active at that moment.

PCM uses OL when:
- cold,
- at WOT,
- in PE,
- during throttle/airflow transients,
- CL is disabled.

VE/MAF determine airmass.
OL/CL determine commanded AFR.

SD/MAF are orthogonal to OL/CL (there exists 4 combinations of these).

PCM also uses airmass to determine ignition timing and transmission pressure.

Make sense?

joecar
June 7th, 2010, 06:53 AM
If the ECM is using the richer of VE or CFOL - the problem is figuring exactly which table is providing the AFR. Does the VE BEN 'ONLY' pickup a value when the AFR is coming 'FROM' the VE table? If so, could one do a BEN map for CFOL table?As was said above:

VE provides cylinder airmass.

Richer of CFOL and/or PE (if PE enabled) provides commanded AFR.

voda1
June 7th, 2010, 09:27 AM
So the VE provides the airmass, and the richer of CFOL and/or PE (if PE enabled) provides commanded AFR.
Then the ECM calculates the fuel required.
We then measure the result with the wide band.

5.7ute
June 7th, 2010, 10:13 AM
Yes voda1. Good description.
wesam, do not command stoich at any time with a custom OS while doing AutoVE. By default, any time you command stoich with a custom OS STFT's are active.(Short Term Fuel Trims) This will skew your data & make the data incorrect.
In the low load areas (up to 75kpa) I use an AFR of 14.5 while doing AutoVE. This is far enough from stoich to prevent the trimming from occuring.

wesam
June 25th, 2010, 06:46 AM
Yes voda1. Good description.
wesam, do not command stoich at any time with a custom OS while doing AutoVE. By default, any time you command stoich with a custom OS STFT's are active.(Short Term Fuel Trims) This will skew your data & make the data incorrect.
In the low load areas (up to 75kpa) I use an AFR of 14.5 while doing AutoVE. This is far enough from stoich to prevent the trimming from occuring.

Sorry i just saw this post
So why in the AUTOVE tutorial there is 14.63 from map 15-55 @ 80-100* C ??

wesam
June 25th, 2010, 06:49 AM
i tried to put 14.63 as in the AutoVE tutorial and i reached to EQ=1 +-.01 in nearly all cells in 4 runs so should i now go back and command some thing like 14.5 instead of 14.63 to not let the STFT to come active ?

joecar
June 25th, 2010, 07:12 AM
Yes, correct, do two things:
- make sure there are no cells set to stoich in B3647,
- disable B4206.

wesam
June 25th, 2010, 07:15 AM
B3647 is not available in COS1
B4206 already disabled
should i change the 14.63 in the CFOL B3605 to 14.5 ?

joecar
June 25th, 2010, 09:59 AM
B3647 is not available in COS1
B4206 already disabled
should i change the 14.63 in the CFOL B3605 to 14.5 ?
Then in B3605.

I am not sure with COS1, so yes do it regardless.