Lean Cruise Tables
06-22-2008, 06:20 PM
#1
Lean Cruise Tables Lean Cruise Tables have been added to Tunercats (what i use) and EFIlive
HPT? i do not know. any one been able to get them to work? been playing with tunercats got it where it should work but it does not. doing a lot of search on a few forums and get alot of conflicting information.
paying $4.30 for 93 octane would be less painfull with a couple more mpg.
not too bad now 21.2 mpg city\hwy
any mpg gains w\underdrive pulley?
HPT? i do not know. any one been able to get them to work? been playing with tunercats got it where it should work but it does not. doing a lot of search on a few forums and get alot of conflicting information.
paying $4.30 for 93 octane would be less painfull with a couple more mpg.
not too bad now 21.2 mpg city\hwy
any mpg gains w\underdrive pulley?
06-23-2008, 12:33 AM
#2
The GM programing has code written into it that make it ignore the lean cruise tables in everything but the 04 GTO (since it was an Aussie based car) for emissions reasons 
. There are a few people that have found a way to "fix" it, but they really won't share how. You have to actually do it in the hex code.
. There are a few people that have found a way to "fix" it, but they really won't share how. You have to actually do it in the hex code.
06-23-2008, 09:58 PM
#5
06-24-2008, 06:48 PM
#8
Translate those commands into Hex and then search for them in the OS... Then change it to a NOP.
If we had a way to know the IP [instruction pointer's] address and had all this BS on a bench we could step through and see what the IP points at in general operation. It would take a long time but we could do it.
06-24-2008, 08:47 PM
#9
06-25-2008, 10:21 PM
#12
Yea, you can spoof the tune but the PCM doesn't know whats going on. You can use COS5 but it doesn't pull timing like this would. Doesn't the GTO lean tables pull timing plus have a latency so it doesn't take effect so fast?
Last edited by 2002_Z28_Six_Speed; 06-25-2008 at 11:00 PM.
06-26-2008, 06:23 AM
#13
TECH Fanatic
iTrader: (25)
Join Date: Nov 2001
Location: SC
Posts: 1,784
Likes: 0
Received 0 Likes
on
0 Posts
You should not be pulling timing to help gain MPGs, you either leave timing where it is or add some.
And the GTO tuning goes off of MAP and RPM or MPH, been a while since I have actually looked at it and it does have a time offset, which we usually pull down to like 1sec or something like that and then change the MAP range in which it comes in, and of course when you tip in the throttle it comes out of LEAN Cruise immediatly and you never know the difference.
This set up on an 04 GTO M6 19"TSWs with AI Heads with stock cam (for now) will get 30-32MPGs on the hwy.
We have done other tuning on the CTS-V and it gained 12% MPGs buy removing some TM, and changing the O2 mV for stoich.
Remember, the 14.7 is stoich for gasoline (100%) and the narrow bands tell us that should be .457ish on the O2 readings. You can tell the VCM what stoich reading should be either in the stoich box OR better yet, tell it what the mVs should be for stoich. Right now reducing the O2 box by about 100 in the appropriate areas.
And the GTO tuning goes off of MAP and RPM or MPH, been a while since I have actually looked at it and it does have a time offset, which we usually pull down to like 1sec or something like that and then change the MAP range in which it comes in, and of course when you tip in the throttle it comes out of LEAN Cruise immediatly and you never know the difference.
This set up on an 04 GTO M6 19"TSWs with AI Heads with stock cam (for now) will get 30-32MPGs on the hwy.
We have done other tuning on the CTS-V and it gained 12% MPGs buy removing some TM, and changing the O2 mV for stoich.
Remember, the 14.7 is stoich for gasoline (100%) and the narrow bands tell us that should be .457ish on the O2 readings. You can tell the VCM what stoich reading should be either in the stoich box OR better yet, tell it what the mVs should be for stoich. Right now reducing the O2 box by about 100 in the appropriate areas.
06-29-2008, 04:22 AM
#15
TECH Fanatic
Join Date: Aug 2005
Location: Sunny London, UK
Posts: 1,690
Likes: 0
Received 0 Likes
on
0 Posts
Yeah the latest Holdens have the lean cruise removed, probably due to NOx emissions.
The trigger is g/cyl and time over a set speed based. Basically so it knows you are cruising anyway and not in stop start.
You can use a Custom OS to do much the same, but not with as much control. Personally I would run 15:1 everywhere except PE at the drop of a hat. The nice thing with Lean Cruise is when you dont need power, just economy, you can lean it off to 17:1 which the stock holden tune gets to.
If you wanted to run it in a non holden platform you would need to flash the holden OS into your camaro/corvette etc or at least the relevant segment of it plus cal. Then make sure the platform check was bypassed.. NOP instead of the JNZ or whatever. Easier said than done.
Personally Id check out open loop fueling
The trigger is g/cyl and time over a set speed based. Basically so it knows you are cruising anyway and not in stop start.
You can use a Custom OS to do much the same, but not with as much control. Personally I would run 15:1 everywhere except PE at the drop of a hat. The nice thing with Lean Cruise is when you dont need power, just economy, you can lean it off to 17:1 which the stock holden tune gets to.
If you wanted to run it in a non holden platform you would need to flash the holden OS into your camaro/corvette etc or at least the relevant segment of it plus cal. Then make sure the platform check was bypassed.. NOP instead of the JNZ or whatever. Easier said than done.
Personally Id check out open loop fueling
06-29-2008, 10:13 AM
#16
On The Tree
iTrader: (8)
Join Date: Jun 2005
Location: Austin, TX
Posts: 145
Likes: 0
Received 0 Likes
on
0 Posts
The LS1 PCMs use a Motorola 68332 processor (CPU32 instruction set). Translating the code on the EFILive page won't do you much good, as the commands vary by operating system.
Your best bet is to find a disassembler (IDA) and try to identify the lean cruise check routine.
Your best bet is to find a disassembler (IDA) and try to identify the lean cruise check routine.
06-29-2008, 12:15 PM
#17
TECH Fanatic
iTrader: (25)
Join Date: Nov 2001
Location: SC
Posts: 1,784
Likes: 0
Received 0 Likes
on
0 Posts
why go thru all of that? if can be duplicated and just as effective or more effective depending on how you would set up the LEAN on GTOs.
note Hondas are running in the 20's:1 AFR during 'cruise'....
note Hondas are running in the 20's:1 AFR during 'cruise'....
