496Stingray

In the new torque based ECM what exactly defines the torque management during gear changes? I see several threads referring to reducing it by 50-80% etc but in this ECM I do not see anything that clearly defines how reduction is accomplished.
In the TCM there is a "How the TCM finalizes the shift" Option which is set to Engine Torque Management from the factory. Other options are Immediate or Throttle. Immediate made for some ugly shifts.

I dont see a timing table that is referenced during the shift... I have EFI Live Scan Tune V2 Commerical 7.5 and 8.0

Thanks in advance for anyone willing to chime in.

_Rob

JoeyGC5

iTrader: (24)

There are the tables for % reduction that you've seen that rely on tables with predetermined timing values for that % of torque reduction, you can find the but I cant remember where off the top of my head. You also have the same base timing tables used in the shift tq reduction tables as with the tq limiting parametes used in the max allowed axles and trans shafts bits.

496Stingray

Thanks Joey oddly I can't seem to find any of those tables in this thing which perplexes me. Nothing specific to shafts of any sorts like I have seen in the other ECMs. This is the 2011-14 HD which uses a different programming than the non HD trucks, but figured some of this would be the same. I have done the IAT vs Spark and the High Octane tables as well as lowered some of the part throttle shift points below the 52% throttle range so it's not so rev happy. It accelerates a ton better and a massive improvement in mileage just running around town. +4mpg. I still feel an annoying dip in power as the shift completes which I would like to dial back. I'm not even working on the WOT stuff yet just the overall part throttle feel of the truck.

JoeyGC5

iTrader: (24)

On my old 2011, I think the tables were either in the tcm torque reduction section or maybe in the e38 ecm in torque management. Been awhile.

1FastBrick

iTrader: (17)

Is there any way you could post the original factory tune for us to look at?

496Stingray

Attached is the original factory tune file.

The modded file I am currently running only has a few small changes.

• I did validate what I thought about the IAT vs Spark table which is once you cross the 20 Deg Celsuis line the table becomes a spark retard. I decreased its agressiveness by 25% in the 40-75C range and added 20% from the cold side up to 20C.
  
• 30% added to the High Octane Table.
• The IAT reduction was really agressive on this truck even before the adds in the high octane table. The part throttle torque and driveability and mileage are light years better than stock. I always run 93 Octane so might as well gain from it.

Few questions:

• What is the multi-spark for? I mean I know what MSD is but how does that apply to the E38 ECM and why have it there if disabled? Does anyone use that when say running a hotter cam? Why not use MSD at cruise RPM for cleaner burn + mileage? I know coil dwell time will only allow for MSD typically under <3k RPM etc.
  
• Cam position at full throttle: I notice in this talbe that 9 deg @ 6000 is the max. In the L99 files I have seen they run quite a bit more advance in the upper end. Is it logical to think that adding more cam advance to the VVT would bring in more power in the upper end of things?
  
• Cam positions vs High/Med/Low Baro presume they are multiplers for the above mentioned and the VVT spark tables of course would coincide in the overall Hysterisis?

Thanks again guys I am a quick study but also being an engineer I am making small changes and observing the results and asking questions vs nuking my pistons or worse.

Overall once I nail the tuning down I plan a VVT cam upgrade and either turbocharge it or pickup a low cost Eaton from a CTS-V. I am not out to run 9s in my HD truck or anything but really enjoy the rattle of a nicely cammed engine and the grunt a blower will add and the shock value when what appears like a nice work truck tears someone a new one on the street.
Of course we all know its addicting....

1FastBrick

iTrader: (17)

Well, I am out of my element here but what about the B8801 Maximum Engine Torque Table? Have you tried adjusting that?

Also H0162 Vehicle Overspeed Torque Limiting and H0163 Vehicle Overspeed Control?

Seems these might Have an effect Similar to Torque Reduction.


Have you posted up On the EFI Live Forum? Some of the guys can be really helpful there as well.

496Stingray

Thanks. Yah I have a post on EFI Live trying to figure out why they have zero PIDs for my E78 ECM. Makes it difficult to tune when you cannot log or see what's going on. Thankfully I have an LM2 wideband dual channel to get some idea but would have been nice to do it all in one package.

1FastBrick

iTrader: (17)

I forgot to ask, What type of transmission is in this thing?

JoeyGC5

iTrader: (24)

Im waiting for the damn beta release to come out so I can work on two E78 trucks.

You cant compare the car cam phasing timing to the trucks mainly due to the huge weight differences.