VE Table Tuning and the O2 Switch points.

[TFZ_Z06]

I was thinking about cam overlap and the possibility of the wideband and narrow bands (while in CL) picking up a certain amount of o2 from the overlap.
I wonder what would happen if you do a VE adjustment, then turn on CL and immediately adjust the o2 switchpoints so the fuel trims are close to zero.

The idea would be to compensate for the added o2 from the overlap.
When VE is tuned at 14.68, the mixture is potentially wrong depending on the amount of cam overlap.

I can't explain this well. If anybody has tried this, post up. Be interested in your results.

[SSpdDmon]

If the WBO2 is/isn't picking up extra O2, why wouldn't the narrowbands pick it up? Overlap exists regardless of whether or not you run the car in open or closed loop. :)

The real question is, how much of the O2 being picked up is fresh, unburnt air from overlap vs. post-combustion O2 directly related to your AFR. This is why a semi-closed loop OS comes in handy. If you can get the car to idle at say 15.5~16:1 on your WB, that'd probably be much closer to idling at 14.7:1 if your cam didn't have as much overlap.

[TFZ_Z06]

If the WBO2 is/isn't picking up extra O2, why wouldn't the narrowbands pick it up? Overlap exists regardless of whether or not you run the car in open or closed loop. :)

The real question is, how much of the O2 being picked up is fresh, unburnt air from overlap vs. post-combustion O2 directly related to your AFR. This is why a semi-closed loop OS comes in handy. If you can get the car to idle at say 15.5~16:1 on your WB, that'd probably be much closer to idling at 14.7:1 if your cam didn't have as much overlap.

How did you come up with 15.5-16? In theory, this is going to vary based on the cam being tuned.

So, has anybody tried a correction factor on the switchpoints? Obvioulsy, a stock setting will result in a leaner switchpoint, hotter cats, etc. If you have, post up your results.

[mr.prick]

i`ve tried changing the O2 switch points with BEN to no avail.
i tend to run a tad rich in CL with slightly positive LTFTs.:confused:
maybe use a calc.pid based on LTFT,
something like this,
{SAE.LONGFT1}+{SAE.LONGFT2})/2/100+1
you will need a calc.pid to track {B4105}

*CLC-00-200
None 0 64 0.0 "lookup({GM.DYNAIR}, 0,0, 4,4, 8,12, 12,30, 16,36, 20,40,24,44, 28,50, 32,54, 36,54, 40,54, 44,54, 48,54, 52,54, 56,56, 60,64, 64,64, 68,64, 72,64, 76,64, 80,64, 84,64, 88,64, 92,64, 96,64, 100,64, 104,64, 108,64, 112,64,116,64,120,64,124,64, 128,64, 132,64, 136,64, 140,64, 144,64, 148,64, 152,64, 156,64, 160,64, 164,64, 168,64, 172,64, 176,64, 180,64, 184,64, 188,64, 192,64, 196,64, 200,64, 204,64, 208,64, 212,64, 216,64, 220,64, 224,64, 228,64, 232,64, 236,64, 240,64, 244,64, 248,64, 252,64, 256,64, 260,64, 264,64, 268,64, 272,64, 276,64, 280,64, 284,64, 288,64, 292,64, 296,64, 300,64, 304,64, 308,64, 312,64, 316,64, 320,64)"
--------------------------------------------------------------------------
CALC.CLMODE F200 CLC-00-200 None Loop "Closed Loop Mode"

i have`nt figured out how to track bank1 and bank2.

[TFZ_Z06]

i`ve tried changing the O2 switch points with BEN to no avail.
i tend to run a tad rich in CL with slightly positive LTFTs.:confused:
maybe use a calc.pid based on LTFT,
something like this,
{SAE.LONGFT1}+{SAE.LONGFT2})/2/100+1
you will need a calc.pid to track {B4105}

*CLC-00-200
None 0 64 0.0 "lookup({GM.DYNAIR}, 0,0, 4,4, 8,12, 12,30, 16,36, 20,40,24,44, 28,50, 32,54, 36,54, 40,54, 44,54, 48,54, 52,54, 56,56, 60,64, 64,64, 68,64, 72,64, 76,64, 80,64, 84,64, 88,64, 92,64, 96,64, 100,64, 104,64, 108,64, 112,64,116,64,120,64,124,64, 128,64, 132,64, 136,64, 140,64, 144,64, 148,64, 152,64, 156,64, 160,64, 164,64, 168,64, 172,64, 176,64, 180,64, 184,64, 188,64, 192,64, 196,64, 200,64, 204,64, 208,64, 212,64, 216,64, 220,64, 224,64, 228,64, 232,64, 236,64, 240,64, 244,64, 248,64, 252,64, 256,64, 260,64, 264,64, 268,64, 272,64, 276,64, 280,64, 284,64, 288,64, 292,64, 296,64, 300,64, 304,64, 308,64, 312,64, 316,64, 320,64)"
--------------------------------------------------------------------------
CALC.CLMODE F200 CLC-00-200 None Loop "Closed Loop Mode"

i have`nt figured out how to track bank1 and bank2.

I'm not sure its necessary to track both banks, since the switchpoint is the same for both banks. However, I have noted not both banks produce exactly the same data, so some adjustment may be useful if carefully done?
If we knew which cylinder was being fired, you would know which were are on. I noticed a bunch of diff o2 sensor datalog params.

At least using the method you listed, you can find out which CL mode the pcm is using, thus play w/switchpoints. Did you notice any sweep in LTFT after changes?

[mr.prick]

I'm not sure its necessary to track both banks, since the switchpoint is the same for both banks. However, I have noted not both banks produce exactly the same data, so some adjustment may be useful if carefully done?
If we knew which cylinder was being fired, you would know which were are on. I noticed a bunch of diff o2 sensor datalog params.

At least using the method you listed, you can find out which CL mode the pcm is using, thus play w/switchpoints. Did you notice any sweep in LTFT after changes?

it`s not necessary for manual changes, but i know you use the RR/RTACS,
and i have tried to use it this way.

i used BEN factor without much success with changing actual AFR,
i did not notice LTFT changes as i was trying to get AFR to match stoich
and i only "played" with this for a few outings. (maybe 3 times)
like i said it may need to be changed with LTFTs some how.

[SSpdDmon]

How did you come up with 15.5-16? In theory, this is going to vary based on the cam being tuned.

So, has anybody tried a correction factor on the switchpoints? Obvioulsy, a stock setting will result in a leaner switchpoint, hotter cats, etc. If you have, post up your results.
It's not really a rule of thumb to say 15.5~16:1. I was just throwing those out there as a "for instance." Finding the right AFR for your application will probably require a little T&T - looking for a leaner than 14.7:1 AFR that is smooth and creates the most vacuum. :)