fuel limiting before 3200

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May 4th, 2018
85c20lb7

fuel limiting before 3200

Don't slaughter me too hard, or do if you please. I've searched to no avail.

07.5 LMM 12628594 os, dsp5 conversion. 12mm stroker, 100 overs, 68mm vgt in valley, 480 over. Truck has been driven well on purchased tunes without 480 for 5-6 years. Added more air, wanted more duration to compliment that air. A little data logging gave me some limits to work around.

I modified the duration, and timing of the non dsp slot and slot 4, adjusted pedal position a to 886 in the bigger end and tapered it back, I figured I'd get those bugs worked out first.

non dsp or dsp 4, truck main injection flow rate does not even come close to calculated flow rate until about 3200rpm. Once I breach 3200 it comes alive. The injector pulse being commanded matches closely to the main injection flow rate.

I can not seem to record torque data on v7.5. says gm.trqeng_b is not a valid pid when I'm connected the e35b lmm ecm. no torque pids are once connected.
So I added it in on bbx and used the v2 for what it's for, not worrying about your laptop flying when having to brake hard. Pulled log through explorer, loaded it on the 7.5 scan, won't play back.
I've read about this somewhere else. I haven't researched it yet, but v2 is all up to date, as is software. So next step, watch the data and worry about that other stuff later.

So I go on another run, find that the trqeng_b maxes out at 443 ft lbs. this can't be right, I haven't changed any torque based fuel tables, pedal position should be requesting 897 ftlbs, it's main fuel rate is 72mm3, calculated fuel is 95mm3, but pulse time is 931uS which is in between 70-75 @ 180 MPa which pressure was at. Once I reach 31xx-32xx the main rate goes to 105 and calculated is within ~10

does this on the non dsp and dsp 4. so I know I'm sharing the issue in another table. I have at this point maxed b1117, b1118, b1119, b1186, b1128, b1192, b1152, b1153, b1154, b1155, b1156, b1157, I've modified d5196 in the tcm played with d5197 on every setting.

obviously I've got to get some data recording figured out, It clearly not going to help much if the v2 trqeng_b is real, so it would track in the wrong parts of the tables. I am not commanding 72 anywhere in the 443 sections.

I do not see what is requesting the reduction in any multiplier but allows it to go away at 3100-3200 area. Outside of continuing this trend of table by table disabling shit until it cooperates, It's making me nutty. I appreciate all opinions and thoughts.
May 5th, 2018
GMC-2002-Dmax

What is MAF reading currently?

Adding a second charger and relocating the MAF Sensor is likely the issue.

Get a MAF Data log of a 100% stock truck, then compare to your logged flow, I bet the flow on the truck with the twins is off quite a bit.
May 5th, 2018
85c20lb7

Quote:

Originally Posted by GMC-2002-Dmax

What is MAF reading currently?

Adding a second charger and relocating the MAF Sensor is likely the issue.

Get a MAF Data log of a 100% stock truck, then compare to your logged flow, I bet the flow on the truck with the twins is off quite a bit.

Pretty sure maf is maxing out, I multiplied by 1.52 based off original sizing to that massive pipe on the front of the charger. I'll check shortly.

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May 7th, 2018
85c20lb7

Quote:

Originally Posted by GMC-2002-Dmax

What is MAF reading currently?

Adding a second charger and relocating the MAF Sensor is likely the issue.

Get a MAF Data log of a 100% stock truck, then compare to your logged flow, I bet the flow on the truck with the twins is off quite a bit.

I'm seeing 86.69 lbs/min currently. Previous tune that that was in truck saw 76.29. I rescaled to see 76.29 maxd out and found no difference. I rescaled my boost map a bit with no difference either but a tighter desired vs actual.
I've noticed this time as I didn't let it warm up, it doesn't seem to fuel cut until above ~158F on coolant temp. Yet all fuel coolant modifiers start going to zero at 140-150.

I wanna think it's something in the torque fuel tables but with no modifications on those tables from a base file.

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May 7th, 2018
85c20lb7

1 Attachment(s)

I obviously have some cleaning up to do on the boost map still. The requested torque should be 897, it's never above 430 on the norm, peaks higher than that, but the mm3 doesn't line up with the torque based fuel tables, modifiers are off at the temp the truck is at as they are all zeros. Even when the desired boost matches the actual at the end of the file, it never changes the requested torque. I'm not sure where the data is being pulled from at this point. If anyone wants to review this data and makes you jump out of your seat at where you would be looking, feel free to let me know
June 24th, 2018
BigTexas68

Do you have any DTC's present? Is it showing reduced power on the dash display?
Your vane % is at 100% almost the entire time. You are hitting a limiter that's probably related to boost/airflow.
June 27th, 2018
Bdirtymax

Quote:

Originally Posted by 85c20lb7

Don't slaughter me too hard, or do if you please. I've searched to no avail.

07.5 LMM 12628594 os, dsp5 conversion. 12mm stroker, 100 overs, 68mm vgt in valley, 480 over. Truck has been driven well on purchased tunes without 480 for 5-6 years. Added more air, wanted more duration to compliment that air. A little data logging gave me some limits to work around.

I modified the duration, and timing of the non dsp slot and slot 4, adjusted pedal position a to 886 in the bigger end and tapered it back, I figured I'd get those bugs worked out first.

non dsp or dsp 4, truck main injection flow rate does not even come close to calculated flow rate until about 3200rpm. Once I breach 3200 it comes alive. The injector pulse being commanded matches closely to the main injection flow rate.

I can not seem to record torque data on v7.5. says gm.trqeng_b is not a valid pid when I'm connected the e35b lmm ecm. no torque pids are once connected.
So I added it in on bbx and used the v2 for what it's for, not worrying about your laptop flying when having to brake hard. Pulled log through explorer, loaded it on the 7.5 scan, won't play back.
I've read about this somewhere else. I haven't researched it yet, but v2 is all up to date, as is software. So next step, watch the data and worry about that other stuff later.

So I go on another run, find that the trqeng_b maxes out at 443 ft lbs. this can't be right, I haven't changed any torque based fuel tables, pedal position should be requesting 897 ftlbs, it's main fuel rate is 72mm3, calculated fuel is 95mm3, but pulse time is 931uS which is in between 70-75 @ 180 MPa which pressure was at. Once I reach 31xx-32xx the main rate goes to 105 and calculated is within ~10

does this on the non dsp and dsp 4. so I know I'm sharing the issue in another table. I have at this point maxed b1117, b1118, b1119, b1186, b1128, b1192, b1152, b1153, b1154, b1155, b1156, b1157, I've modified d5196 in the tcm played with d5197 on every setting.

obviously I've got to get some data recording figured out, It clearly not going to help much if the v2 trqeng_b is real, so it would track in the wrong parts of the tables. I am not commanding 72 anywhere in the 443 sections.

I do not see what is requesting the reduction in any multiplier but allows it to go away at 3100-3200 area. Outside of continuing this trend of table by table disabling shit until it cooperates, It's making me nutty. I appreciate all opinions and thoughts.

At what throttle % are you requesting 897 ftlbs? Looking at the data you sent the highest I see is 505 for a second.