Adaption in OBD II. SAAB with piston as ground for spark.

["Neil Deshpande" <Ndeshp@xxxxxxxxxxxx>]

Jim Conforti mentioned that adaption in OBD II engines did not permit =
accurate dyno testing.  Another example of a completely new point from =
him.

As I understand it, this means that the engine chip adapts its map to the =
driving style of the driver.  Therfore, you have to 'clear' the chip to =
baseline each time you want to dyno the car to get repeatability since the =
car would 'learn' from the dyno run and presumably do 'better' next time.  =
I wonder if I am correct.  Jim?

I also wonder about the following:

1. Does the chip rewrite itself only after the car is switched off or is =
it changing on the move.   The latter would mean it is impossible to get =
dyno numbers even if you clear adaption.  You would have to cancel the =
adaption process altogether.  Is this even fair to the chip?  I guess this =
is possible.  What isn't?  But, it would be difficult, I imagine.

2. Aren't there adaptive transmission chips too?  Does this mean the a car =
that has been raced would do better than one that has not on the racetrack =
because the transmission would shift better for those conditions?  Of =
course, I'm talking of automatics, but the SMG might do a similar job.  =
Perhaps you could even race the same track a couple of times before a =
final and do better as a result.

3. Does the chip improve noticably after only one run and how many HP?  =
Will the stock OBD II chip ultimately get near as good as a Jim C. chip =
after it has learnt the way its owner drives.  I guess the Jim C. chip =
would have a head start of a sort.  I imagine the stock chip would never =
really get better as the JC chip would have gains over it due to the =
factors that have been discussed here before - making use of the fact that =
you will use premium fuel, take care of the car so emissions remain OK, =
etc.

4. What kind of percentages does the change involve?  I would guess there =
is a limit imposed by BMW on the amount each parameter can change.  =
Perhaps emissions imposed limits.  These would be the limits that Jim C. =
woud reoptimize in his chips.  Right?

Jim, if you do expatiate further, it would be a pleasure.

On an unconnected issue, Mark O. mentioned a SAAB engine that used the =
piston as the ground electrode.  Does anyone else know of this. I would =
like to know more about this.

Neil Deshpande
88 325 is
89 325 ic

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