how to set lean cruise

[bifster]

I read the post in the first thing there and nuthing in it helped me out at all as im a newb. I was poking through the tables today and noticed I could set a lean cruise and would really liek to as I do alot of cruising and not too much town stuff so it would save me at the pumps so if anyone could help me please give me all the info posible thanks

[Tordne]

The short version :)

Lean Cruise is ONLY available/possible on Holden/HSV vehicles. There is specific code in the Operating System that prohibits it from being activated on any other platform.

Preempting your next question... No the standard Operating Systems WILL NOT be modified to allow this function to be available on other platforms as it would make the modifier liable.

No the positive side :) if you are a EFILive Commercial or Workshop license owner then you can, with the version 3 or 5 Custom Operating systems use the B3647 Open Loop Fuel Table to command a leaner AFR at various RPM vs. MAP cells. This would basically require you to run in Speed Density mode (MAFless) and in Open Loop so that you command something other that stoich.

Hope that helps you some.

Cheers,

[neil]

What's the best settings for the Australian version after Lean Cruise has been turned on?

Regards,

Neil.

[Tordne]

Sorry, can't answer that one. I have had it disabled for over a year. I just use the Open Loop fuel table if I want to run lean.

[bifster]

O ok thanks. the only other thing i was thinking of doing was to lean the mixture out some across the etire table as i noticed running the car at about a 15.4:1 ratio it wrked really well and didnt smell at lights haha but anyways I guess ill have to get more seat time on the car and the software thanks

[joecar]

Yes, collect and analyze as many logs as you can, the more the better. :cheers:

[limited cv8r]

You really need to modify the lean cruise table then check it with a wide band if you have one. There are other setting as well that you can play with like engage,disengage speeds and also time till engagement.

[Garry]

What range of B3647 could be set to a leaner value (which), without endangering the engine or cats? I checked some HSV setups, but their Lean Cruise entries didn't seem setup ...
Like, e.g., 1200-3000 RPM & MAP through 30, with 15.4 or so ... !?

[ringram]

If you use lean cruise Id keep the cells the same but shoot for 15.4:1 in those cells thats the most economic according to a few graphs and docs Ive read.
Any leaner and power drops more than economy rises etc.
Same goes for B3647

Cats die from rich mixes, I dont think lean hurts them much, if at all.

[Garry]

If you use lean cruise Id keep the cells the same but shoot for 15.4:1 in those cells thats the most economic according to a few graphs and docs Ive read.

... which would be?

Cruising on the Autobahn, I usually run around 85@1800 in 6th ...

[Tordne]

If your 6th gear ratio is the same as mine (0.50:1) then you would probably be more economical to run higher revs in 5th gear... It sure is for me.

[TAQuickness]

If your 6th gear ratio is the same as mine (0.50:1) then you would probably be more economical to run higher revs in 5th gear... It sure is for me.

Depends on the cam ;)

[Tordne]

Any cam will have to work its ass off to push a .5:1 gear around town :)

[Garry]

Hm ... I'm usually running with very low MAP at that time ... guess I would need to do some comparisson, and logg something to calculate the MPG ... stock cam, btw ...

[ringram]

... which would be?

Cruising on the Autobahn, I usually run around 85@1800 in 6th ...
Tisk, tisk, such doubt :)

Take a look at the bottom of here http://www.racetep.com/halmeter.html

Some discussion here too http://www.findarticles.com/p/articles/mi_qa3828/is_200008/ai_n8914887

Ive seen the same thing in a few more places which I cant find at the mo. My blog has a graph I nicked from another article with the same conclusion.
http://r8transformation.blogspot.com/ (http://photos1.blogger.com/blogger/2602/1737/1600/StoichiometricGraph.jpg)

See the 12 August web log for the graph. I cant link directly to the image due to blogspot restrictions on links

I tried running way leaner as Tordne will attest. Ive settled on 15.4:1 as my friend for now.

[Garry]

Tnx Richard!

So, what RPM/MAP area would be a good range to put 15.4 in the B3647 table? I tried with 20MAP 1600-4000, with one field around it (1200, 4400, and 25 MAP 1200-4400) at 14.88 ... city driving seemed a bit sluggish though when starting to roll ...

Btw, why doesn't b3647 have any MAP values below 20?

[ringram]

Thats a good question.
Im not sure, but maybe under 20kpa you can lean out further as it should be decel and dfco should work is wonders here anyway. Just off idle I run 14.8:1 and I run lean cruise and b3647 based pe.
I guess thats why lean cruise is good as it only kicks in once you are cruising usually at constant speed. You really want richer for acceleration.

With the stock cam you can try 15:1 under 60kpa and see how that feels.
Leaner normally needs a little more timing to burn properly too.
Thats why I dont run leaner than 15.4:1 any more... it felt too slugish. Defeated the purpose of the 5.7L engine!


Basically just play around to see what feels nice. Maybe 40kpa to 70kpa 1500rpm to 2600rpm for the cruise zone?