Re: Who knows what these two sockets are for?

[Paul Fox <pgf@xxxxxxxxxxxxxxxxxxxx>]

 > All of the current BMW's use an O2 sensor in a closed loop Fi 
 > configuration. 

i had heard that.

 > The Triumph Fi is an Open Loop system, that's why we 

i didn't know that.

 > can get different maps and CO tunes loaded. In fact closed loop 
 > systems on bikes suck since if the bike is setup to lean there isn't 
 > any adjustment. Just ask a BMW owner with a surging bike ( from a too 
 > lean mixture) about it!

i don't understand why that's follows.  i understand that an open-loop
system is essentially predictive ("given how i believe the engine and
exhaust system to have been designed, then with these input
measurements, i predict, but can't know, that the correct results will
be obtained if i provide X fuel and Y timing advance"), where a closed
loop system is reactive ("given the current input conditions, and the
fact that the O2 in the exhaust is a little off, i know i should make
the following adjustments to the fuel and timing"). 

but in both systems, there are decisions being made about how much
of this or that (fuel and timing) to provide at any given instant.
and a new tune, or an adjustment to the current tune, could influence
either type (open or closed loop) of system.

in fact, it sounds as if the triumph (sagem, actually) system can work
either way, since the O2 sensor is optional.  (optional to the bike, that
is -- i assume a given "tune" either requires it or ignores it).

my opinion?  i think bmw just has lousy engine management software --
i don't think it's a matter of "open-loop" vs.  "closed-loop" systems.

paul
=---------------------
  paul fox, pgf@xxxxxxxxxxxxxxxxxxxx (arlington, ma, where it's 19.8 degrees)
  'oh-oh Sprint RS, '91 VX800, DoD #1462, AMA #545601

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