Lean Cruise with E78?

[496Stingray]

Wanting to know if anyone has calibrated a lean cruise on an E78. L96 6.0
If so any pointers are appreciated.

[GMPX]

Just keep in mind, the lean cruise concept was removed from GM's code late in the LS1 days, it was never in E38, E40 etc and certainly isn't in E78. To make it happen you would need to do some trickery to the tables.

[496Stingray]

I thought that was/would be the case. Curious if anyone has tried it and or if we have access to the necessary tables to make it work?

[GMPX]

I don't know if such tables would exist, I think you would only be skewing the ECM's intentions.

[496Stingray]

Yeah my thoughts were to lean out the low load portions but as you said with the way the new ECMs work I'm not certain if I can fool it into doing what I want. Silly to me that they got rid of it, as lean cruise works well and saves a ton of fuel. I have a turbocharged stroker 6 cylinder in my Grand Cherokee that cruises in the 16.8 range on flat ground and averages 24 hwy on road trips. It's such a primitive system aka JTEC jeep that it doesn't have knock sensors or MAF. I'm running 3 bar MAP, closed loop with a turbo and gnarly solid lifter cam in it.

[GMPX]

Emissions during lean cruise was the problem, GM had to put a check in the LS1 code to make sure only Holden vehicles (nothing in the US) could run in lean cruise. I guess by the time the E40 ECM arrived they just ditched it totally to work on AFM instead.

[496Stingray]

Yah N0x BS... and having enough fuel in the mix to light up the cats etc..
What kills me is the logic that using 40-50% more fuel is better for the environment than slightly elevated NOx. Isn't burning less I'm general already better for the planet?? :-/

[496Stingray]

Just checking my logic. Even if I were to "fool" the ECM somehow we can't do it in the VE tables. Is there not a table anyplace in this ECM that specifies commanded fuel in closed loop? We have PE commanded and cat protection enrichment etc.

Logged it today and it's steady in the 14.3-15.1 range considering that's on 15% corn gas it's not terrible.

[ScarabEpic22]

Should be a Stoich AFR table for ethanol % in there, but it's a single row (or column, been a while since Ive looked). I.e. you cant adjust stoich at 2000rpm at 65kPa, just at 10% ethanol set to 14.1, 20% set to 13.6, etc.

[496Stingray]

Should be a Stoich AFR table for ethanol % in there, but it's a single row (or column, been a while since Ive looked). I.e. you cant adjust stoich at 2000rpm at 65kPa, just at 10% ethanol set to 14.1, 20% set to 13.6, etc.

Correct it is there but as you said it will just skew the entire closed loop section lean. Gone are the days of commanding a lighter fuel mix under x/kpa and x/rpm. Unless there are tables we dont yet have access to then I am about out of ideas.