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View Full Version : Lean out rate


Extinct
March 22nd, 2009, 01:34 AM
OK, working on enabling lean cruise and I have a question regarding lean out rate.

I have been looking for a stock Holden or GTO bin file that actually was enabled from the factory and haven't been able to find one thus far, they all seem to be disabled based on the factory speed setting that requires a speed in excess of 200mph before it is enabled. I was going to use the stock Holden examples as a starting point, they are .0010, however given that the ones I have seen aren't enabled I'm not sure that means much.

What exactly are the units of the lean out rate anyway - is it EQ ratio/cam phase, per rev, per cam sensor pulse ?

Anyone experiment with this setting with any success ?

I would think you would only want the lean cruise lean out to kick in after a few seconds of steady state cruising, so as not to kick in during transients.

Any help would be appreciated.

Thanks

Tim
gmperformancecentre
March 22nd, 2009, 07:53 PM
here's my stock tune with has lean cruise enabled.it's a stock Holden VY SS Commodore 6 speed manual factory tune
Extinct
April 22nd, 2009, 09:56 AM
Bringing this back up, Paul can you answer this question:

What exactly are the units of the lean out rate anyway - is it EQ ratio/cam phase, per rev, per cam sensor pulse ?

Thanks

Tim
Highlander
April 26th, 2009, 05:08 AM
Doesn't matter really... play with it and see the commanded AFR how it leans out. Then, check to see if its too fast or to slow and causes the car to hesitate or miss...

Otherwise... you want it as fast as possible, because if you are going to spend 150s driving to spend another 40s more to get to the final lean state you are NOT going to save that much fuel unless its a long trip. Ideally what I would want is that if I am at that G/Cyl and RPM that its pretty much always that unless I am transitioning.

THe smoothness of the engine will come when no variation of fuel is occurring.
Extinct
April 27th, 2009, 11:31 AM
Matters to me, I like to know/understand the original GM program/intent.

Paul, a little help here ?
Highlander
April 27th, 2009, 04:04 PM
What i wanted to say is... trial and error, you will figure out what the number means.