SCT PRP A/F Tuning

DLF

DLF

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OK, I admit it, I'm stumped!

I've been using the PRP since it became available (my Racer # is 12), but I haven't been able to figure this one out yet.

In first and second gears my A/F ratio is right about where I've commanded it, but once into third gear it gets progressively richer.

I don't see any parameters that would cause this, but obviously, I've missed something. Also, I don't see how this could be mechanical, but if anyone has any thoughts, I'd love to hear them.

What you see in the chart is MAF Volts, RPM, and A/F Ratio.

Hints?

BTC0 PCM

LM206011100.jpg
 
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There is some scalar... its for enrichening the mixture under high sustained loads... and its in some stupid place... you are on version 3.xx?
 
kustomizingkid said:
There is some scalar... its for enrichening the mixture under high sustained loads... and its in some stupid place... you are on version 3.xx?
Click to expand...

Advantage 3.3 Build 88.15

I see both "Oil Overtemp Mode" under Engine Temp Limits and "Lugging Mode" under Fuel, but both require the ECT to exceed 254 before they're supposed to kick in, and my ECT never exceeds 190.

And there's also an "Exhaust Temp" section, but as the PCM doesn't have a sensor to monitor the exhaust temp, I haven't given it much thought.
 
This has got to be it. :cool:

This Scalar is under Engine Temp Limits/Exhaust Temp.

It appears that the PCM calulates the exhaust temp based upon tables (since there isn't a sensor) and then takes action after a specified period of time.

If I set the last value to my lowest desired Lambda value of .8670 (12.7 A/F), I'll bet it corrects the issue.

I'll find out on the Dyno @ Carlisle tomorrow.

TempControl.jpg
 
Well, it was ok today on the Dyno. I'll do a long pull @ the track next week to verify that it's fixed, probably Tuesday @ Atco.
 
As a follow-up, I was able to solve the first problem, but found that I had a lean spike @ the hit of the throttle.

Solved that as well.

Now to get the A/F ratio down to where it's supposed to be following the intial hit.

LM206151102.jpg


LM206161102.jpg
 
Tune is fine, just pulling your man boobies.

I will call as up-grades demand a re-tune tweak.

See...... tune is OK, left the plant yesterday with a little anger, :D

marks.jpg
 
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