CAMMED LT1 TUNING ON CAMARO SS VS SS 1LE - ANYONE ELSE HAVING ISSUES ON 1LE's?

This is just more theory then anything. I've tuned a ton of Camaros but I can't help but notice every time I get a 1le SS the idle tuning gives me trouble. I can do the exact same mods on a regular manual SS and they dial in very easy and chop excellent with a bunch of idle timing.
On the 1LEs I find it that I'm fighting with the torque tables every time trying to get positive timing at idle.
Recently I used the new BTR 225 cam on both a 6gen SS and SS1le. The SS chopped out of the gate and only took some minimal tweaks to perfect. Car sees 10-15 degrees at idle. Put the same cam in a SS 1Le and the thing is stuck at negative -1.5.

The other thing I noticed was they don't have much spark timing from the factory on the 1le's.

So I went through the tunes and compared an 18ss with an 18ss1le. Main differenced I found was the external load was a bit different and the speed control density was different (1le was a zeroed out table).

Never messed with speed control density before.

Any thoughts

without seeing datalog and tune hard to see or tell the cause

There are tables that we don't have access to at play. Prime example - take a 16 or 17 silverado "I tune more trucks than anything, so I run into this more" - with their original calibration they'll tune in fairly easily - will seem like pretty much anyone can tune one. Now install the latest updated calibration via Tis. At this point you're going to relearn how specific everything needs to be dialed in as they won't idle right anymore, dip when coming to stops bad to the point of stalling. They won't even start up right anymore - you'll run into problems with them firing and immediately dying or catching and flairing... Without learning how to dial in the density table and torque model correctly you'll never ever get it to run right. I really wish I knew what GM changed and could change it back myself ;) If anyone is using EFI, does it happen to show what's different?

Put your MAP Virtual Torque tables back to stock, but keep a decreased value for Airmass Virtual Torque. Then lower your VVE by 5%-8% in the idle area and increase your MAF by 5%-8% in the idle area and see if that doesn't start moving timing in the direction you want it. Essentially you want to tell the ECU that the throttle blade should close more. If your airmass and VVE are off, the Virtual Torque tables are not going to work well because everything is jacked up.

Are you logging the PID's for MAF Airflow, VVE Airflow and Dynamic Airflow? What do these values look like at idle before my recommendations and then after?

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Originally Posted by GHuggins

There are tables that we don't have access to at play. Prime example - take a 16 or 17 silverado "I tune more trucks than anything, so I run into this more" - with their original calibration they'll tune in fairly easily - will seem like pretty much anyone can tune one. Now install the latest updated calibration via Tis. At this point you're going to relearn how specific everything needs to be dialed in as they won't idle right anymore, dip when coming to stops bad to the point of stalling. They won't even start up right anymore - you'll run into problems with them firing and immediately dying or catching and flairing... Without learning how to dial in the density table and torque model correctly you'll never ever get it to run right. I really wish I knew what GM changed and could change it back myself ;) If anyone is using EFI, does it happen to show what's different?

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That makes a lot of sense. I just wish we could control the timing and the idle airflow like the good old days. I might look into EFI to see if they are getting more files

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Originally Posted by TriPinTaZ

Put your MAP Virtual Torque tables back to stock, but keep a decreased value for Airmass Virtual Torque. Then lower your VVE by 5%-8% in the idle area and increase your MAF by 5%-8% in the idle area and see if that doesn't start moving timing in the direction you want it. Essentially you want to tell the ECU that the throttle blade should close more. If your airmass and VVE are off, the Virtual Torque tables are not going to work well because everything is jacked up.

Are you logging the PID's for MAF Airflow, VVE Airflow and Dynamic Airflow? What do these values look like at idle before my recommendations and then after?

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Yes, I'll give this a shot.

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Originally Posted by JASON11WS6

That makes a lot of sense. I just wish we could control the timing and the idle airflow like the good old days. I might look into EFI to see if they are getting more files

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You can control idle airflow - it's the last column in the startup airflow table. Just keep in mind the higher it is the lower timing is, but you have to raise it to keep idle right with cams and everything, so just something to work around. Other tables that add timing - lowering DD if it's axle torque based, raising external load, lowering reserve, lowering adaptives, but again a lot of these are counter productive. You can skew things like Jason said and still keep all the rest happy if you will.

I know there are some things we don't have access to that GM changes that really throws things off. If you have efi and can download the files please let us know what's different in them ;)

You know, I've noticed the same thing with 1LEs. Their idle logic just seems to be a tad bit different than an SS car. I typically have to do a little extra massaging of the VVE,MAF, and like Huggins mentioned, the last column in the startup airflow table.

GTFO. The 4 sec line on the start up airflow is where the idle airflow is controlled? Learn something everyday. It took a while to dial it in just right with the VVT and VVE tables. Once the VVE was perfect at idle I started with a fresh vtt and got it right.

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Originally Posted by JASON11WS6

GTFO. The 4 sec line on the start up airflow is where the idle airflow is controlled? Learn something everyday. It took a while to dial it in just right with the VVT and VVE tables. Once the VVE was perfect at idle I started with a fresh vtt and got it right.

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I didn't know it either for a long time. Always blindly adjusted to get startup airflow right - didn't put 2 and 2 together for the last column until someone else told me ;)

You should also be able to shift the torque model like I illustrated in your personal cars thread a while back to get idle torque right for map and maf. I haven't fully gotten into shifting things like Jason mentioned yet. Still need to try that. I was just recently informed by one of the engineers that did the torque modeling that the map side of the model directly controls the throttle, so having it "up" vs the maf side makes sense with that....

After reading this thread I went and tried the mods Jason recomended and still was having problems idleing and misfires, I found a video of a guy who had problems with a big cam also in a gen V and he showed how he unlinked the torque tables and lowered the idle area in each spark range by a set 50 lbft
so what I did was lower the idle area to match 0 lbft in each spark table at what airmass I was at when idling and did the same for my map table to match the kpa at 0 lbft and my car woke up and is chopping and running great now with no misfires at all, I learned a lot after my ecm went bad causing me to chase my tail for a couple of weeks but then the new ecm wouild not run the car as before so there is a change in the new bin file calibrations GM is puitting out for me to have to change the idle up like that.
Thanks for the input from all of you it helped me out a lot. Got my car back to brerathing fire now.

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Originally Posted by Jabercrombie

After reading this thread I went and tried the mods Jason recomended and still was having problems idleing and misfires, I found a video of a guy who had problems with a big cam also in a gen V and he showed how he unlinked the torque tables and lowered the idle area in each spark range by a set 50 lbft
so what I did was lower the idle area to match 0 lbft in each spark table at what airmass I was at when idling and did the same for my map table to match the kpa at 0 lbft and my car woke up and is chopping and running great now with no misfires at all, I learned a lot after my ecm went bad causing me to chase my tail for a couple of weeks but then the new ecm wouild not run the car as before so there is a change in the new bin file calibrations GM is puitting out for me to have to change the idle up like that.
Thanks for the input from all of you it helped me out a lot. Got my car back to breathing fire now.

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I use stock idle logs compared to the altered vehicle logs to adjust the models back to the factory agreeing with one another specs and then lower or add to it from there. Still an incredibly big pita that will almost make you look like an idiot to the ones you're doing it for, but it's the only way I know to have them right.

Do you care to walk us through how you did it? Especially the unlinking part. Maybe even the vid you're talking about.

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Originally Posted by GHuggins

You can control idle airflow - it's the last column in the startup airflow table. Just keep in mind the higher it is the lower timing is, but you have to raise it to keep idle right with cams and everything, so just something to work around. Other tables that add timing - lowering DD if it's axle torque based, raising external load, lowering reserve, lowering adaptives, but again a lot of these are counter productive. You can skew things like Jason said and still keep all the rest happy if you will.

I know there are some things we don't have access to that GM changes that really throws things off. If you have efi and can download the files please let us know what's different in them ;)

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I havent found anything different in the tunes with EFI. Got a 2017 getting a transmission next week and sending it to Stealership to get TCM flashed. Ill get him to flash the ECM as well and read it off and compare.

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Originally Posted by RDF1

I havent found anything different in the tunes with EFI. Got a 2017 getting a transmission next week and sending it to Stealership to get TCM flashed. Ill get him to flash the ECM as well and read it off and compare.

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Well crapo. I wonder if there's any software that would show us what they changed. I know they become a real pain to have everything right after the fact.

Make sure to tell the dealer to flash the ecm even if it doesn't show to need it. Otherwise they may not flash it...