Are have a stronger will than me thats for sure!! Or stricter penalties for your sins
Are have a stronger will than me thats for sure!! Or stricter penalties for your sins
Andrew
EFILive Crew
Stupid question - is there anything in EFILive that will tell you whether or not this is activated? I've got my "Commanded AFR" graph up on my dashboard, but it only seems to go down (presumably due to PE), rather than vary from 14.68 @ cruise.
I don't think there is a PID or anything - that I've seen anyway (didn't look real hard).
You can have a look at all the enables in the tune file and see when it might become active...
You're right though. The Commanded AFR will richen when PE mode is active, or you are in Open Loop with the B3647 table of a Custom OS.
Andrew
EFILive Crew
I noticed in the lean cruise section that you can set the speed at which it occurs.
Seems it would be good to drop the point of operation down to 30 or 40kms to improve economy around town
Regards.
Neil
Well I've got a customer coming back this week for some more economy tweaks ( likes the extra grunt but "feels like he needs something else" lol ) so I will be spending my time on lean cruise setup. Will post my results or findings this week.
Mike
That would be great Mike.
Neil
Same here - as for whatever reason, the "Commanded AFR" hasn't changed on mine, even though I've dropped the enable speed to almost 25 km/h. I don't want it that low, but I'm trying to see if it will indicate when it comes on in a log file.
Check all the enablers and multipliers.
The are timers for run time, and off idle, as well as the speed enablers and disablers.
Then there is the table that defines the amount to lean out the mixture when the enablers are meet.
But also check the Coolant Temp Multiplier table to make sure that the multiplier is a value of NOT 0 in the areas you're expecting, otherwise it will all just do nothing
For example in the stock setup Lean Cruise does nothing below around 80*C ECT temp, so if your logging at around 50*C ECT then don't be surprised if Lean Cruise isn't working
I've never bothered running or testing Lean Cruise before but it seems to be a hot topic right now with all the new members - I'm almost temped to have a look at it just so I can help you all out.
Cheers,
Andrew
EFILive Crew
Alright guys and gals ( being "PC" ) heres the scoop on lean cruise from todays efforts on an auto 2003 SS Holden 5.7
Did a machine effort tuning the thing to start with, VE table averaged around 14.3 to 14.6 on the wideband from the dyno up to around 75kpa and up to 3600rpm. I have this hooked up via my Flashscan Ver2 onto my laptop which is a fantastic help for tuning etc etc.
Anyhoo, first of all I experimented with the O2 switch point map as my AFR always sits on about 14.4:1 with the O2 STFT on when doing holdens. Other factory cars always sit bang on 14.7:1.
Since we are on the subject of economy I adjusted the O2 switch point down from 540 to about 400 and achieved a steady 14.6:1. Quite chuffed!
And an easy way to tweak your cruise AFR.
Next I adjusted the lean cruise Km activation to 55km to make the learning process quicker. Now, here's the interesting bit......
Up to 55km the STFT is working nicely giving me a 14.6:1 steady, commanded 14.63:1, over 55km the STFT turns off ie: no feedback, and the commanded afr dropped to about 15.9:1 and actual afr to about 15.2.
The lean cruise map points I set the same at 0.08 to make the changes easier to track as you pass thru them.
Now when you pass through to a point on the Lean Cruise map (to the right) that has a "0" on it the commanded AFR goes back to 14.63:1 on the actual AFR goes back to whatever the AFR was your VE/MAF runs when the STFT is turned off...in my case 14.4:1 as I had spent time getting a good base tune.
Of course if you activate PE mode based on TPS all this goes out the door as you would expect.
So to have lean cruise actually work properly from a technical aspect you would have to have your VE table SD tuned perfectly to 14.63:1 and your MAF table calibrated to match so when you pass out of lean cruise into a "0" at higher load areas you would still acheive 14.63:1.
Interesting eh?
Tomorrow I will experiment with the lean cruise map settings at different rpms and loads to see if the amount of EQ ratio reduction alters the actual AFR by similar amounts at each point. A bit of mucking around but I think its worth doing.
phew
Also a point worth noting for you SD tuners out there is the when you are SD tuning, lean cruise will effect your AFR actual causing the VE table to have some funny skews at certain points ( I found this out the hard way ) so when you are SD tuning make sure you lock out lean cruise at 400km/hr. Also don't make the re-enable the same as enable as this also causes problems, make it say 10km/hr difference.
Cheers,
Mike
feedback from customer after setting up lean cruise was good except for a "vtec" like effect under load in 3rd or 4th gear. This is of course when you pass in to a "0" point in the lean cruise map and the AFR goes to the base VE setting, so the car picks up a bit with the richer mixture. Have decided that the load point of 0.4 grm/cyl is to far for the lean cruise to be active and will set this back to "0" and see if that improves things for him. Set the other areas between 0.09 and 0.07, this pulled the AFR down to 15:1 to 15.3:1. Will keep you posted on mileage readings.
Mike
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