Best in the business

[blindsquirrel]

Fuel Trim Cells later LS3 and other later model vehicles that use Airflow Mode boundaries

EVAP Open
0 - 5 defined by the LTFT Airflow Mode Purge On boundaries
6 - Idle
7 - Decel

EVAP Closed
8 - 13 defined by the LTFT Airflow Mode Purge Off boundaries
14 - Idle
15 - Decel

[LS ROB]

I honestly believe the best tuners in the business are already on this forum except for one up north. This is just seeing all the tunes that I personally go in behind on or people I talk to.

Heck, if you read through a few different threads, I feel it's evident that what you said is true. I just didn't know if some of you all had someone that you would recommend or reach out to whenever you have issues with a tune. If it sounded like i was discrediting guys from the forum; that was not my intent. I'm just ready to be able to drive this thing and be able to enjoy it.

[GHuggins]

Didn't mean anything bad by that Rob

The one up north I was referring to if he's still there as I'm not 100% sure was the one at Lingenfelter. He's one of the other ones I know of that gets into government stuff.

[LS ROB]

Thanks blind! I've always wondered about which number represents what. I appreciate your help!

[LS ROB]

Didn't mean anything bad by that Rob

The one up north I was referring to if he's still there as I'm not 100% sure was the one at Lingenfelter. He's one of the other ones I know of that gets into government stuff.

All good brother. I appreciate all you have helped with man. I'm going to work on putting this thing in open loop and going for a ride. It may be friday before i will be able to but i'll report back.

[Ben Charles]

Sent you back an email… I would change at least half the tune

[LS ROB]

Sent you back an email… I would change at least half the tune

I'll check it out.

[Estep40511]

I'll check it out.

If Ben cant fix it, Id say it cannot be fixed. The best tuners for sure are on this thread for sure. They will help you get it fixed!

[Alvin]

Its while i'm cruising in the light load area that roughly starts around 1500rpm.

It would be interesting just to let someone else drive it and see if they think its normal or not..

I see a wide range of customers who think a car that stalls and is hard to start "runs good"

Then other customers that want to tell you 3 months ago when they merged on the highway they felt a hiccup and ask how we can address that in the tune.


I'd fix a lot of the idle timing, run it in speed density, and experiment with if closed loop is making this thing drive worse or not.. then take steps to modify integral, proportional, and offset on the o2's to see if they can be happy.. but like I said before.. this is on the edge of what will work with narrow band closed loop.

One important thing I'd encourage.. and I don't say this to offend you. But give up on what you think things should be like and let a professional take over with what he knows is best. People get hung up on things people with 0 credentials/experience but tons of post say on forums. If your professional tuner thinks SD is the way to go.. go with it.. make a decision (with open mind) after their done if its better or not.

[07GTS]

just as a test i noticed your max torque timing table ecm12660 right at the cruise rpm and around the airmass the values go from 50 to 34 between 16g to 24g cells, going between those two values it will be changing the torque quite a bit for cruise, not sure if its factory like that or not looks a little odd ill attach tune modified for test, im really not sure just clutching at straws

[LS ROB]

just as a test i noticed your max torque timing table ecm12660 right at the cruise rpm and around the airmass the values go from 50 to 34 between 16g to 24g cells, going between those two values it will be changing the torque quite a bit for cruise, not sure if its factory like that or not looks a little odd ill attach tune modified for test, im really not sure just clutching at straws

Hey man, thats all im doing right now too, so i appreciate you trying to help. I took Alvin's advice and decided to let someone have a go at it. I was told they could fix it no problem so we will see how it plays out.

[pannetron]

First, a caveat: my ECU is a GMPP E67, yours is an E38, so my experience may not be directly applicable. Looking at your tune and log, two things come to mind. You mentioned you have different injectors so I assume they're bigger. Your O2 short term trims move around quite a bit, so did mine before I reduced the limits in the [ECM] 12486 - Closed Loop Proportional Limit table down to 0.500. Next, the torque limits in your Spark Smoothing tables (I have smoothing enabled...) are higher than mine; when I reduced mine to 30 lb/ft in the three tables, it helped eliminate the slight bucking I felt at light throttle 4th gear cruise. Another change I made in the Spark Smoothing section was to increase the values in the High Torque Threshold table to 590. Not sure why I landed on that value but the idea was to force the ECU to use only one table, the Low Torque Gain table. The values in your High Torque Threshold table are right around the delivered torque values your log shows when you're at cruise so the ECU is likely switching between the Low and High Torque Gain tables.

My cam is 215/247 0.629/0.656 121 LSA so it has much less overlap than yours. Thinking about the [ECM] 12470 Closed Loop Integrator Delay, I reduced the values in my table since my exhaust valve opens much earlier than stock, maybe like your cam. Even with long tube headers, my guess is that the O2 sensors are seeing the effects on the injector pulse swings earlier than the stock values would expect with the OEM later exhaust valve openings. I attached my table.

Dunno if any of this will help you but it did for me, trialed in over years of whittling on my tune ;-)

2023-02-10_13-07-02.jpg

[LS ROB]

Thanks for the info Pannetron. I've been working with someone but i havent heard back from them in a bit so they may be tied up on other things. I think i may have just solved this though. All along, this issue has pulled timing while im driving at a steady cruise. It correlated with my adaptive spark tables so i went in and halved them. by the time i reached the top of my driveway, i could tell this was the right move. I have now 0'd out the adaptives in the "coast" table and will go for a drive when the wife gets home. Who knew that the "Coast" table that pulls spark if it sees an overspeed, had a "drive" table that also pulls spark INSIDE the COAST table!? lol i didnt. I knew it was there but didnt know what or how to fiddle with it until 30 min ago.

[GHuggins]

If it fixes it Rob, that's great to hear. You can also go after it if it is only the adaptives via the right hand side of the adaptive controllers airflow tables. I only ever experienced that once before with a cammed and supercharged ls3. Didn't think that was going on with yours as I kept going after what was causing it to go into idle mode in the first place. Of course I didn't do your tune, just helped out when I could from time to time Really hope you figured out

[LS ROB]

I think that's got it. I'll have to do some more testing to be certain but the short drive i got to take felt good. I'm not sure if that's the real "fix" or a band aid fix that will lead to other issues but it helped.