RE: Adaption in OBD-II and questions

[Land Shark <lndshrk@xxxxxxxxxxxx>]

> From: "Neil Deshpande" <Ndeshp@domain.elided>

> I wonder if I am correct.  Jim?

  Actually, the car adapts so that any operation in it's adaptive
  ranges reverts to lambda one.. so if you enrich the wrong areas
  of the part throttle maps you waste your time and actually 
  are ENLEANING the wot map!

> 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? 

  What we do is actually clear adaption then DISCONNECT all four sensors
  running the car until the CE light illuminates (about 0.001 sec on
  those darn M3's ;)

  Then test...

  Then tune..

  Then repeat

> 2. Aren't there adaptive transmission chips too?

     I couldn't answer that one.. but I have recently joined 
     with someone who is a guru in the Transmission field, and
     he's working on some special trans chips for me.. I'll ask him

> 3. Does the chip improve noticably after only one run and how many HP?

     It might get worse if were incorrectly calibrated.. forget what
     you have read.. the DME doesn't adapt to "driving style" or any other
     such nonsense.. it adapts to EMISSIONS criteria.. and if you do 
     everything JUST right.. once the chip is adapted to the actual
     engine particulars of the car.. it only changes for weather

> Will the stock OBD II chip ultimately get near as good as a Jim C. chip

  Not even close.. the chip isn't adapting to the way you drive ...

  It works like this (again.. these are EXAMPLE, not REAL numbers)

  Let's say the adaptive range is 1000-3000 rpms.. throttle less than
  50%... 

  You're in traffic.. 1/3 pedal.. 55mph, 5th gear.. SMACK in the 
  range.. the O2 sensor is seeing if it has to go RICH or LEAN
  more than the opposite.. and if it does for some amount of time
  then the adaptive trim changes in the opposite direction by the
  needed percent to "center the window"..

  Once that number is created, though.. even if you are running
  full throttle 4th gear at 6000 rpms.. the number is still USED

  In general.. as the car runs.. it gets slightly leaner because
  all maps are tuned *slightly* rich for safety.. 

  Adaption cannot change the spark advance to increase it.. only
  to decrease it from that which is programmed..

  Adaption doesn't increase performance...

> 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.

   ADAPTION can change the mixture (generally) up to +/- 25%

> These would be the limits that Jim C.  woud reoptimize in his chips.
> Right?

  No.. by tuning outside of the adaption areas I *COULD* double the
  fuel if I wanted to.. although it would be a sign of insanity ;)

  The problem isn't a lack of adjustment.. it's a lack of stability
  when testing the vehicle!

  Jim

------------------------------