I have one of these and one of the reasons I picked it was lean cruise capability. I was told today there was a different Aussy model that did this....is this true?
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I have one of these and one of the reasons I picked it was lean cruise capability. I was told today there was a different Aussy model that did this....is this true?
It's not the PCM box itself but the calibration operating system it is flashed with. There are lots of different model and type vehicles that could be flashed in that 0411 PCM. That is what determines if it has lean cruise capabilities or if it is enabled. As a rule the EPA did not allow GM to enable LC on domestic made for USA vehicles for emissions reasoons. Some GM Austrailian made Holdens had it enabled. There are ways to enable it though on certain calibrations if it is available and not enabled. Again it depends on the operating system. And don't expect to gain much in MPG with it enabled.
Yes, he said properly tuned the 0411 will return very good mileage. My EBL has the hwy mode enabled and does well.
I have used actual lean cruise in TBI ECMs, TPI ECMs and the EBL as well as with the 0411. I have also used open loop pseudo lean cruise calibrations in vehicles that did not support lean cruise like my Hemi Ram. I have found that well tuned lean cruise will often return 10-15% better fuel economy at steady cruising speeds than without. That is running 16-16.5:1 air/fuel ratio with a bump in timing as the slower burn of the lean mixture can often result in the need of 4* or more timing added. Furthermore running on the lean side of stoichiometric will actually drop EGTs. A good example of this can be found in most aircraft pilots manuals with information on setting cruising air/fuel mixture. Most information out there has a pilot adjust to find peak EGT (which is at stoichiometric) and then further lean it 25-100*F. On an air cooled airplane substantial reduction in cylinder head temperature is also noticeable.
For example one such study can be found here.
https://docs.lib.purdue.edu/cgi/view...xt=techdirproj
Fast355, always read your posts with interest. What vehicle/tune have you run with the 0411 that allowed lean cruise? I'm not familiar with LS ecu's but I think I read somewhere with HPtuner/EFIlive that that option is/was not available (grayed out).
I have an Express van with what started life as a L31 and run a coil per cylinder setup. I have both HPTuners and TunerCatsOBD2.Quote:
Originally Posted by dfarr67
The parameters are not grayed out in the calibrations but it is disabled in the OS. You can populate the fields but it takes an OS patch to enanle LC. I also use HP Tuners and TC OBD2 and have LC enabled in a daily driven 04 Silverado 4.8L with a OS patch using TC. Again with no where near a 10-15% improvement in mileage. I have HPT logs showing it enabling at highway cruise speeds. Starting with Post #26 in this thread it describes a way to enable LC on blue/red pcms if you only have HP Tuners and can not patch the OS with TC. Just ignore the pissing match Aknovaman tried to turn it into. https://ls1tech.com/forums/pcm-diagn...-cruise-2.htmlQuote:
Originally Posted by dfarr67
One thing to consider the 4.8 does not make alot of torque anyway and is always under load pulling the truck. My 350 makes ALOT more torque lower in the RPM range and turns more RPM than most as delivered GM setups. With lean cruise enabled I get 19 mpg highway with 5.13 gears and 1-ton running gear from a 215/223 cammed 350 with 200cc intake port aluminum heads.Quote:
Originally Posted by 2xls1
That van has a 8.1L in it now?
Mine is a 383cid SBC 24X conversion, also looking to change out the 700r4 for a 4l60e.
My 1997 Express has a 350 Vortec with aluminum heads, marine intake and headers. I was at one point going to swap an 8.1 into it. I went with a much higher reving 350 and gears instead.Quote:
Originally Posted by dfarr67
My 1983 G20 has an 8.1/4L80E with the GM 454/502 HO cam and 2nd gen Camaro long tube headers. I am running the factory V6 4L80E torque converter and 2.73 gears.
My brother has a 1987 G20 with a LQ4/4L80E too.
I'm looking forward to building a 4L60E to replace 700r4 for my eventual 24X conversion- I suppose I could reuse the converter I have now- no issues but no idea how long they last- when I ordered it many years ago I had all the tricks done to a stock converter, but its still a stock stall. With efficiency and a little towing in mind I was thinking about doing the same thing in the 4.3L version- in all honesty I haven't been convinced to date the spend the $$$$ for a billet version for my application- I understand a little bigger clutch and some improvement in apply piston but I am wondering if is worth it in a non racing environment. To give you a flavour of my logic- I just sold off a 4L80E, to me the changeover fitment issues and bigger parasitic drain vs a well built 4L60E my awareness of how to drive them as a lighter duty trans didn't justify the change- 700r4 after a few repairs has given very good service EXCEPT for my inability to get the governor right for me.
After having light duty transmissions I will never go back to them if I can keep from it. For GMs it is TH400/4L80E or Allisons for me. I somehow managed to break a Powerglide behind a 305 in my Vette a few years ago. I have cooked numerous 700r4/4L60E/4L65Es and Dodge 545RFEs along with a Jatco 7 spd in my Infiniti M56S. I have also grenaded a couple of engines. Needless to say I run my stuff HARD and nothing I drive stays stock for long.Quote:
Originally Posted by dfarr67
Well I think I can agree with different driving styles- most of my issues come from quality of re manufacture (from various rebuilders) or maybe a setting not caught in time ie TV cable (one issue I haven't had). Maybe the 4L80 is the better choice but the deeper I got into it I didn't like it. To be fair to me though I see most of your stuff is 2 wheel drive that makes life alot easier.
Let me ask this another way....my impression is that you (Fast355) have the time and the knowledge to squeeze most out of what you have. Since you also seem to be serious about working your vehicle- how does the V6 converter compare to what GM blessed it with? What do I have to spend/spec for a converter?