Sudden increase in Air/Cyl

[Mileage]

We tried Swingtan's VVE dial in guide on our E67 boosted application. The parameters seemed to match the E38 very closely. We experienced very rich conditions at part throttle operation over about 90map. Idle and light throttle was okay as well as WOT but it would go rich at moderate throttle either on the way up or down. It stayed rich as I held the throttle constant for several seconds, ruling out a transition issue. We noticed tha Air/cyl jumped, therefore commanding more fuel. The theoretical air/cyl is about 67 non-boosted, 100 at 150 map. If I can attach the dashpage you can see it jumps much higher (160) as I let off after a WOT blast and shift and blast.

Any suggestions as to what goes into the air/cyl calculations or what to look for? Thanks

[GMPX]

In the coefficients tables, is the last column all zero's?

[Mileage]

I will check tonight.

[rhit_rs]

Mileage checked tonight and the last column (MAPSq) is all zeros.

[scdyne]

Can you post an image of your VVE?
At around 4200 RPM you go from one MAP zone to another and if you haven't massaged them much from stock then you might be in an area that is a continuation of a calculation that originally stopped at 87kpa.

Did you remove the MAF or just disable it? I found that other than initial start-up I had success just disabling it and not physically removing it from the system.

I assumed that the IAT needed to be calculated at that point still and left it in. The problem is that I didn't spend enough time looking at weather it was 100% right because it worked for me.

Having relocated the throttle body to the other side of the engine and the MAF for that matter how clean is your MAF calibration?

Also does the supercharger bypass valve open and close like it's supposed to or is it always closed right now?

[rhit_rs]

I'll have to leave the posting of the VVE table up to Mileage, but it's not much different than before we tried disabling the MAF (at bit more fuel under boost at high rpm). We followed Swingtan's guide to VVE tuning and disabled the MAF as well as unplugged it. The engine will run well at WOT once it gets through the sudden change in Air/Cyl.

The IAT is in the LSJ intake manfold and separate from the MAF sensor.

We are planning to use the VVE table to calibrate our MAF. We changed it some to correct for the tubing size prior to adding the supercharger, but we have not adjusted it since.

The bypass valve is opening and closing as it should.

[Mileage]

Adam,
It looks like rhit rs has answered your questions. I can post the VVE image tomorrow but I enlarged it and looked it over carefully last night. No irregularities in the area where we are going rich. Values are well below WOT areas. Nice smooth surface.
Do you know where GMPX was going with the question about the zeros in the last column of the table?
Thanks for the help.

[GMPX]

EFILive automatically fixes the MAP_SQ column to zero, without that done you can get some very weird airflow values calculated, it's a bug in GM's ECM code.

Cheers,
Ross

[Mileage]

Here is the VVE graph as requested. The air per cylinder in the dashpage above tells the story. It goes way up at part throttle both on speed up and slow down.
To recap, we had been driving the car with the MAF connected and it ran good albeit a little rich for safety. It seemed to be getting a couple of hickups that got worse as time progressed so we decided to follow Swingtan's guide and tune MAFless also making sure that the fuel trims were inactive. Light throttle and WOT were okay but moderate throttle was very rich, missing with black smoke. I have searched the forum some. We had added "one" to the calibration values early on. I did not see any other hints of the problem. Thanks for the help.

[rhit_rs]

The attached log file clearly shows the problem Mileage and I are having. Any ideas on what is causing this?