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View Full Version : Lean cruise patch working for 2003 A4 Vette OS 12221588


Treurentner
October 18th, 2008, 06:33 AM
Hi,

for those who have never seen lean cruise working I added a log where you can find a commanded AFR above 14.63 :).
After using the merged patch from Joecar for that OS it was not working. I found different patch addresses between Phat_B and Joecar. Phat_B was right (I appended the right .cax file)!! and so I could successful do a LC-log.
Since I autocalibrated the VE via my Roadrunner I can say that the commanded AFR´s were very!! close to the wideband. The feeling while driving was very good, no fear on running dangerous lean.
I have two EGT gauges to controll the header temps. At speeds of 120 km/h I have arround 430° C (16.5:1) at speeds of 150 km/h (17:1) I have arround 500° C. Watch the .tun to see at what loads what AFR´s are commanded. Something above that speeds (load) LC will be commanded OFF.
The transition of 14.63 controlled AFR to lean cruise is very smooth and if there was no Wideband you would not feel it. If you come on the throttle to accelerate slightly you will notice a very slight hesitation as the load increases up to the moment when 14.63 AFR is commanded.
So I´m very satisfied with the results, it saves between 1 and 2 l per 100 km, I´m now again at 9 l / 100 km for cruising in our 600 hp Supercharged Corvette C5.:cucumber:
I was running this tune at a cricle track http://www.stc-motodrom.de/ for over 2 hours without any problems today.

Many thanks to all that made this patch availiable for non Holden cars.

Kind regards fom Germany:cheers:

Marco
joecar
October 18th, 2008, 07:07 AM
Marco, thanks...:cheers:

Updated post #4: showthread.php?p=80784#post80784 (http://forum.efilive.com/showthread.php?p=80784#post80784)
GMPX
October 18th, 2008, 10:57 AM
After using the merged patch from Joecar for that OS it was not working. I found different patch addresses between Phat_B and Joecar. Phat_B was right (I appended the right .cax file)!! and so I could successful do a LC-log.
Glad it's working for you.
Just a word of warning, you mention that the patch address was wrong in one of the .cax files, the lean cruise patch is altering the PCM's operating system code, if at some stage (due to errors) the wrong data is being patched it will almost certainly result in a dead, never to be bought back to life PCM....check and recheck the patches.

Cheers,
Ross
vzsv8
October 21st, 2008, 10:47 PM
Marco,
Take a look at B5908, Fuel mixture spark correction. It adds extra spark when lean cruise is active, it is used in all the Holden tunes and it improves the throttle response. This can indirectly improve economy by allowing a higher gear at low throttle.
Check the setting for 2001,2003 and 2003 from Holdencrazy.
I have lean cruise set to operate at much lower speeds and the timer set to have it come on earlier.
DFCO has a big effect on economy as soon as the 'cruisin' stops as well.
Cheers, Steve
Treurentner
October 22nd, 2008, 03:22 AM
Marco,
Take a look at B5908, Fuel mixture spark correction. It adds extra spark when lean cruise is active, it is used in all the Holden tunes and it improves the throttle response. This can indirectly improve economy by allowing a higher gear at low throttle.
Check the setting for 2001,2003 and 2003 from Holdencrazy.
I have lean cruise set to operate at much lower speeds and the timer set to have it come on earlier.
DFCO has a big effect on economy as soon as the 'cruisin' stops as well.
Cheers, Steve

Hi Steve,

thank you for pointing me to that table. I already was aware of this possibility when I did the update from 97/98 PCM to the 411 PCM.
Under WOT it gave me 6 extra degrees of (unwanted) spark that was retarded automatic the same amount. So I zeroed this table out.
For the light load condition with lean cruise it is beneficial and i will try to use it. But to be right, the engine should be hold under these light loads on an eddy current dyno and then real time spark adjusted to meet the point of lowest vacuum (i.e. highest torque / VE).
I will do it that way after my new engine is swapped in (forged 382 cui is nearly ready to install). It will be very interesting what mpg can be reached with a 220/ 230 XER cam on an 113 ICL and 117 LSA on a A4 with 3.15 rear. I hope to pass the sniffer test without any problems.
My DFCO settings were already changed and set more aggressive.:grin:

Kind regards

Marco
joecar
October 22nd, 2008, 03:28 AM
Hi Marco,

Please let us know of the test results (your mpg tests, and the sniffer test)...

What are the emissions tests like in Germany...?

Regards and Cheers,
Joe
:cheers: