Ronny

iTrader: (1)

i notice my tunercat "constants" has BLM enabled only 3600 and below. honestly i did not recognize that till today. i was gonna disable PE and look at 3600/4000/4400 logs on a flat area near my home. the VE tables are optimized in areas that were easy to populate past couple weeks. the difficult ones i thought i would still work on as they are as they were in past files before the cam swap. is ther any value or benefits in going there?

refresh my memory. when we go PE does not the ECU use the VE values in that cell we are in just before the PE was involked? IOW if at 2400 rpms and then we involke PE based upon the % change in TPS how does ECU determine the 12.5/1 i have commanded in my PE tables for (all PE rpms)? does it add to the values in cell for 2400 rpms/50 map assuming i was there before PE? or does it use the 3600 rpm table as that is the highest rpms that blms are/were generated? i just changed that threshhold to 4000. will that allow me to adjust at 4000 ? how is it i am seeing blms at 4000 if the TC program was at 3600 for threshold? 4400 seems impossible to log due to high speed required to populate cells.

RBob

iTrader: (1)

Reading your post makes my head hurt. So instead of an answer for each question I'll generalize how the ECM operates. '7747 & '8746:

When the ECM goes into PE mode the commanded AFR is changed to the value from the PE AFR vs RPM table. As the RPM changes the ECM will track the RPM AFR value of that table. There is no locking of the AFR at the entry to PE mode.

In PE mode: Learn is turned off and the INT is locked at 128. If the BLM is < 128 it is ignored (128 is used). If the BLM is >= 128 it is then used. The upper BLM RPM limit is only used during learn. IOW, no learning takes place above that limit (such as above 3600 RPM).

However, the use of the BLM table extends past this boundry. So when in PE mode (or not in PE mode), there is no upper RPM limit for the use of the BLM cells. They extend to infinity. This is also true for the upper and lower MAP limits. These limits only affect learn, not the usage during fueling corrections. And, the BLM cell is use will also change to reflect the changing MAP/RPM values.

The best way to tune the upper VE table areas including high MAP, is to force open loop, set the BLM limits to 128, and use a WB. Change the VE table to match the commanded AFR. For the commanded AFR you will need to flatten the open loop AFR tables (two of them). This way you will know what the AFR is being commanded to be (unless using a Lockers high speed data acquisition system, then you will have the commanded AFR along with the WB AFR at the same time).

Do the same with the PE mode AFR table, make it the same value at all RPM's. Then you will know what the commanded AFR is. And be able to change the VE table to have it match up to the WB. No need to lock out PE mode, that is not a good idea.

RBob.

Ronny

iTrader: (1)

hope you are feeling better. one more Q.

you state "When the ECM goes into PE mode the commanded AFR is changed to the value from the PE AFR vs RPM table. As the RPM changes the ECM will track the RPM AFR value of that table. " that i was aware of.

Q is: how does the ECU know how to calculate the 12.5/1 or so that is commanded in that table. does it assume the BLM's place the CL A/F at 14.7 and then deliver additional fuel needed based upon the BPW in constants?

RBob

iTrader: (1)

Yep, feeling better, stopped reading and took an aspirin

The commanded AFR is used as part of the PW calculation:

PW = BPC * MAP * ~T * ~AFR * VE * BVcor * BLM * DFCO * DE +- CLT

Note the ~AFR term. That is the inverse of the AFR ratio. Need to use the inverse or FA ratio to make the PW larger as the AFR decreses (gets richer).

RBob.

Ronny

iTrader: (1)

thanks getting better at this. point of interest. had a bog late last year and early this month which i felt was AE related. at tip in, especially engaging clutch, there was a hesitation and then car would go. also slight bog first to second shift in normal traffic accelleration. all else was good. i ended up taking out considerable AE/MAP and adding considerable AE back into AE/TPS. this AM temps were about 45 deg and it appears the bog is gone in CL on a warm intake manifold. next will enrichen OL A/F coolant temp values and i suspect i will get better drivability after initial startup. it is encouraging to see positive results.

Binder

Bringing a old thread back from the dead and trying to understand it........
The way I understand this is if I set my BLM limits (both) to 128 and adjust my bin as attached I can then log with the WB and adjust values to the target AFR of 11:1? Afterward I could then change the bin values back to where they were (minus the VE table) and would not need to further adjust for upper RPM ranges above 2000 RPM?
My goal is to adjust upper RPM ranges but I've adjusted these tables throughout even though my PE RPM threshold is 2000 RPM's, Would this be correct?