Very limited power from standstill. 2016 L96/E78 ECM/6L90e in '88 Truck

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Can someone please tell me why I have very limited power from a standing start? It won't even spin a tire on dirt. This is a 2016 L96 with E78 ECM and 6L90e retrofitted into a 1988 Chevy truck. I have attached the tune file and a log file with several short pulls from standstill through 1st gear. I assume TM is doing this but really I am clueless. I searched tirelessly in and outside these forums, so if I simply missed the answer please help a newbie out with a point in the right direction. I'm hoping it's just in need of a few cells being tweaked...thanks in advance, Dalton

EDIT: I changed back to an older tune and logged. That fixed the problem but WHY? 2 new files attached.
1st 2 files are tune and log WITH the launch acceleration issue.
3rd and 4th files (before Doc) are an older tune and new log WITHOUT the issue.

Doesn't look like you are running the factory emissions parts on this swap from looking at the DTC's. You missed a few settings you need to disable still. COT (cat over temp) must be disabled and the cat test under the engine diag's exhaust tab need to be disabled. That may stop the test/lean condition that is showing up with your fuel trims at idle.

Also click edit > navigator > exhaust. Then disable the catalyst warm up as well.

While we are doing stuff, change some of the PE settings so that it can actual work. Lower the enable pedal from 89% down to like 50% Remove the 8,192rpm delay and change it to like 1,000rpm.


What gears and tires is the vehicle running?


Clean up your logs too. You have things like trans temp, engine oil temp and many other things being logged like 5 times each.

Yeah rear O2, Evap and such are removed. 4.10 rear gear and 31.5" tires. Both reflected in the calibration. Gonna look now at the things you suggested. thanks.

Must be an old tune because it says 3.42 gears and 32in tall tires using the gear/tire wizard.

Or you only changed the gear size using the speedo tab.

If you used the gear tire wizard from the get go it will do everything for you. You need to use that so it can auto scale the transmission settings as well for the different tire size and gears.

I had changed it in the Speedo Tab/Calibration and it shows it was changed. Speedo was just a touch off with only gear/tire size adjustments, so I played a little with the tire revolutions per mile setting and got it spot-on. I went ahead and used the wizard as you suggested.

Loaded adjustments as prescribed. No change. Power won't come along till roughly 3,000 rpm or 15 mph. I mean it feels like literally 50 lb-ft of torque...

See if you can get another log with some of the torque channels. I'd be curious as to what they are showing. Even some of the torque mngt channels.

Did every else come from the donor vehicle too. Like the pedal assembly, air intake.

Not sure how to go about logging torque channels but can try. It's all from the donor vehicle from throttle body to exhaust ports. The only mods are cold-air intake and exhaust system.

Look at the Electronic Throttle > Throttle Area Limits > Max % vs RPM. It's limiting the throttle to 37% until 2400 RPM. Also raise the Max Torque > Peak Torque.

Russ Kemp

Thanks Russ. Your prescribed changes seemed VERY logical; I would have bet they would do the trick, but didn't. Made no difference, so I didn't bother with a new log but the new tune is attached in case I got it wrong.Attachment 91678

I can't say if its related to your problem or not, but have you tried putting the OE MAF curve back in it? The one in the tune provided is wildly different & not very "curve'ish".

had a family situation to deal with; back now. The current MAF curve is all that's keeping me from running VERY lean. The intake tube is larger than stock so the MAF numbers were adjusted to compensate.

Try lowering the TM upshift torque factor on the 1-2. I would start with .5000.

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Originally Posted by 8850

Try lowering the TM upshift torque factor on the 1-2. I would start with .5000.

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The 1-2 upshift is working fine. The problem is a total lack of acceleration from a standstill in first gear. It just doesn't want to take off, like torque management or something is limiting it. Standing still, stab the throttle and barely anything till it gets over 3000RPM or 15MPH, then it starts gaining power.

Quote:

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Originally Posted by sgtbilko

The 1-2 upshift is working fine. The problem is a total lack of acceleration from a standstill in first gear. It just doesn't want to take off, like torque management or something is limiting it. Standing still, stab the throttle and barely anything till it gets over 3000RPM or 15MPH, then it starts gaining power.

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You are correct, sorry. I think then I would change your throttle from 37% to 100% all the way back down to 0. Right now you don't open until 2400 rpm. Engine, airflow, electronic throttle, max %.

I changed throttle to 100% all the way down to 1000RPM, as per Russ K's suggestion and it didn't help. Posted the adjusted tune in reply to his message.

Quote:

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Originally Posted by sgtbilko

I changed throttle to 100% all the way down to 1000RPM, as per Russ K's suggestion and it didn't help. Posted the adjusted tune in reply to his message.

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I haven?t had a chance to compare the files. Do you remember what was changed? I have a 2015 L96. I?m hoping you get yours dialed in! Good luck bud. 😊

what happens with fast torque exit number edits?

I can't seem to identify anything that was changed and would logically affect launch power.

"what happens with fast torque exit number edits?"

I have no idea but from what I understand of Fast Torque Exit, it's for downshift blip and shouldn't affect my issue.