SCMG WOT data log lean spike

[TurboDave]

Anybody care to look at a short WOT pull recorded by the SCMG. I've included the data log and a picture of the graph page showing the lean spike right after the 2/3 shift
I've looked at the VE table, the Target AFR table, and the timing table and can't see any reason for this to happen.

Any ideas?

 

[TurboBob]

look at the VE table, 5200 rpm, the VE is a little too high there, so the correction is going negative, then on the shift you have negative correction that needs to learn itself out, so its lean. The VE might be a touch low at 4400.

B

 

[Mr.Spool]

Anybody care to look at a short WOT pull recorded by the SCMG. I've included the data log and a picture of the graph page showing the lean spike right after the 2/3 shift
I've looked at the VE table, the Target AFR table, and the timing table and can't see any reason for this to happen.

Any ideas?

View attachment 295073

What fuel is being used?

 

[TurboDave]

What fuel is being used?

Straight 93 octane.

 

[TurboDave]

look at the VE table, 5200 rpm, the VE is a little too high there, so the correction is going negative, then on the shift you have negative correction that needs to learn itself out, so its lean. The VE might be a touch low at 4400.

B

Sounds like a good place to start would be to up each column from 4400 to 5600 or so to the values in the column previous to each, if you get my drift.

 

[Mr.Spool]

Straight 93 octane.

Does the lean spike happen randomly or is it consistent?do you log egts?and air intake charge temps?

 

[TurboDave]

Does the lean spike happen randomly or is it consistent?do you log egts?and air intake charge temps?

It's not a random thing. Don't have EGT capabilities. IAT on that run was 53°

 

[TurboBob]

there's nothing random in the way it works, but conditions can vary when driving.

you want a little more "tilt" to the way the VE is falling vs RPM. so the correction doesn't learn negative as the RPMs climb.

 

[Mr.Spool]

It's not a random thing. Don't have EGT capabilities. IAT on that run was 53°

its possible you would have to fatten it up,but there is a point where more octane is neccessary.that point when you raise cylinder pressure and or engine rpm.ways to test are to drop some boost or raise octane with current boost levels.you could also fatten things up and observe results.your iats look good

 

[TurboDave]

there's nothing random in the way it works, but conditions can vary when driving.

you want a little more "tilt" to the way the VE is falling vs RPM. so the correction doesn't learn negative as the RPMs climb.

Ummm, Bob, you lost me on the "tilt" thing. Can you be more specific and explain?

 

[TurboBob]

reduce the VE at 5200

increase the VE at 4400

 

[TurboDave]

reduce the VE at 5200

increase the VE at 4400

Right! I mis interpreted your original post. Now I understand.

 

[TurboDave]

reduce the VE at 5200

increase the VE at 4400

OK, got the changes made.

One thing I forgot to mention. On the Powerlogger, each time I select Monitor, it sets a code 22 (Low TPS). Which is not true because the PLC shows my TPS at .40, and so does SCMG. This is at KOEO.

runnning PL 5.1.0 and PLC 2.6.5

 

[TurboBob]

thats wierd. the error codes come in from the ECM, PLC just displays them. I will look into it.

 

[TurboDave]

Well, one thing I haven't tried is disconnecting ecm memory power. I've been trying to clear them using PL and SCMG. Maybe it's not getting cleared properly.


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