Going from an SD tuning file to full time SD

Hi guys

So I've been tuning my VE and am considering full on SD but I'm having some issues.

My question
- To transition from my SD tuning file, to a full time SD tune, what do I need to change in the tuning file? Do I simply enable fuel trims and fuel cutoff?
The reason I ask is that I am having several issues with the running if I try that.

Issues
- First off, even though the AFR is nearly perfect it has a "ragged" exhaust sound and a slight hesitation on aggressive throttle, doesn't sound right.
- Second, the rpm changes frequently when manually shifting in and out of Park/ Neutral. So, I'll be idling in Park and I put it in Neutral and the RPM jumps to 1,300 for several seconds. I then shift into Drive and the RPM jumps again. Sometimes while sitting at a light in gear the RPM suddenly jumps for a few seconds. Sometimes I'll take my foot off the brake to let it roll slowly in gear and the RPM suddenly jumps. At near closed throttle while rolling along in gear I can feel the power cut in and out, as in not a steady power.
- Third, the shifting is poor. Part throttle shifts are delayed, the RPM hangs. The shifts are harsh.

Now, if I enable the MAF all that is gone. But then the LTFTs are 25+, but it drives GREAT!

I had thought if I get the VE dialed in I could simply forego the MAF tuning.

Any thoughts?
Current files attached.
I've attached the stock file for the engine as well as my current SD tuning file that I have been using and my latest scanning log.

Thanks

To run in speed density you only have to do 3 settings. Set the MAF fail high to 0hz, then set the 3 MAF dtc's (P0101-103) to MIL on first error. Then you can set the dynamic airflow switch over to 7,000rpm if you want. With those settings it will not use the MAF sensor at all. You can log MAF fail status to make sure it's failed if you want.

It is completely up to you if you want to enable fuel trims, some people will keep short term trims only and disable long terms.

Your current tunes do not have the DTC's set correctly for speed density. Also seems you may have a transmission temp issue too, later in the logs it's going into hot shift mode meaning the fluid temp must be getting pretty high.

Thank you for your reply

I've made those changes and will see how it goes this afternoon.

So,...... hypothetically speaking,... if an engine has a "perfect" tune, with the stock MAF, and you disable the MAF to make it an SD tune as you have suggested, will it drive any different?

What I mean is, other then splitting hairs over MPG & emissions, would it be possible for the regular driver of that vehicle notice any difference compared to having an active MAF? As in idling, smoothness, shifting?

When you get it tuned, it will run the same. Some people say a Maf and VE tune is smoother, but I can't tell the difference.

One of the reasons I was asking was that when I drove it with the original tune, as the engine/transmission came in the 2003 Chevy 2500, it drove great! Smooth and powerful, but, the LTFTs were off the chart lean.
I then do a SD tune, LTFTs are near perfect now, but it doesn't have the smoothness or power it did before. I believe that the MAF contributes to the smooth transmission shifts, they are abrupt now.

The files posted below are my current files.

Switch up some of your torque mngt settings.

Under the engine TM there is a table called ETC TPS Max, that is there to limit the TPS to control traction. It could create a less smooth throttle transition if it's limiting movement. I always max that table out to allow 100% everywhere. Then I'd raise the max torque value to 500 over 380 to make sure it's not TM doing anything. Also when you get the ETC table to 100% you need to lower the PE enable torque value to like 80% compared too 100%, everything else can stay how you have it set.

As for the transmission, play around with shift times and pressures. Make sure you have no max adapt shift codes or something like that. Lower shift pressure slightly to see if it helps with shifting. Though I like having nice, firm shifts without bucking in my vehicles.

Changes made. I'll see how it goes tomorrow.

Thanks

Well the driving experience is going downhill fast.

I've been playing with this tune, got the VE within 5%. Driving, well let's just say it drives "OK" for the most part. Off the line and WOT suck!! It's got NO balls off the line, at WOT it misfires and doesn't pull strong. The engine struggled to reach the shift points.

It's been so long since I drove it with the stock tune I thought I'd give it a go.

HOLY HELL what a difference! Off the line it just tears the pavement up, spins like crazy through 1st & 2nd, loud chirp in 3rd. Pulls like gang busters at WOT.
It drives soooooo smooth and is soooo responsive. Shifting like I'd expect from a new Camaro, swift and snug at part throttle and very firm at WOT.

So what is the difference? The LTFTs are waaaay off the charts lean. I watched the WB at all times, never leaner than 11.2 under closed loop. I'm afraid to drive it open loop. When I first loaded the tune my WB read 17 and leaner till it stopped registering. After a few seconds of stumbling the AFR came up and it idled smooth. I did reset the LTFTs before I started it.

So I'm not sure where to go from here. I think I'll abandon my current SD tuning file and start again with the stock file.
What I did in the beginning was tune out the MAF and dial in the VE. Once the VE was dialed in I enabled the MAF and it ran so lean it stalled after a minute and would not start.
I thought that in closed loop, below the 80% WOT it runs off the MAF, unless of course it's tuned out. So why then will it run on the stock tune were the VE is way lean, but when I dial in the VE it won't run?

Both scan logs are of pretty similar driving. Both have a standing start WOT, you can find them about 2/3 of the way through the timeline where the RPM peaks going through 1, 2 and 3

Files attached

First drive of the day is my current SD tune ~ 2003-sierra-6.0-aug-21-sd-tune
The scan log of my first drive ~ aug-21-1st drive is the SD tune. When it was misfiring at WOT the injector duty was over 90%

Second tune is the stock tune ~ 2003-sierra-6.0-stock-no-vats-fans-evap
The scan log of this drive is ~ aug-21-2nd-drive-stock-tune

Thanks

Maybe I'll tune out the MAF and see how it drives.

Speed density does use the low octane timing tables, so you'd want to copy the high octane to the low octane table in SD.

That alone is making it run 5-15 degrees less timing overall under power and that will make it much slower.

I missed that! I know I needed to do that but I must have overlooked it.

So I've copied the high to the low and going for another drive......

You sir are now responsible for making bigger and stickier rear tires a necessity!

That did it! I should have known as a long time mechanic that poor throttle response and a ragged exhaust note that the timing was late.

Now it runs like a champ!

:worship: I thank you very much for taking the time to hold my hand through this.

Now just to tweak my shift points and I'll be ready for the track, oh, after I find some stickier tires ;)

I know this is an old thread, but I am tuning a friend's L83 swop 70 c10. Going with full SD and full open loop.How do I adjust the fueling and can't seem to find ECT TPS MAX. I have only tuned dodge and this seem a bit more complicated than those.

Thanks in advance.

Why open loop?