RE: Load (not)

["Jeff Lloyd" <Jeff@xxxxxxxxxxxxxxxxx>]

Ugg.. Long words make Bobo Brain Hurt...

All Bobo know how to turn round thing and press loud pedal

Bobo like big metal thingy on top of engine and Wire thingy
Bobo can turn wire thingy and motor make pretty
Or ugly sound Bobo says computer evil

Bobo needs screwdriver, not computer

Bobo
(BOBO for president in '04)
Brought to you by (friends for Bobo and the National Carburetor Association)


(argh back to work)


- -----Original Message-----
From: owner-bmw@domain.elided [mailto:owner-bmw@domain.elided]On Behalf Of Jim
Conforti
Sent: Tuesday, November 07, 2000 1:26 PM
To: 944@domain.elided
Cc: bmw-digest@domain.elided
Subject: Load (not)

Unfortunately, you've fallen victim to the disinformation.

The "barn door" aka Vane AFM does NOT "max out" at 3-4000 rpm.

All of this complete BS about Motronic comes directly from
father Bosch who apparently allowed some writer to copy sections
verbatim from the L-Jet Manual over to the Motronic Manual.

(bad, BAD plagiarist!)

In Motronic, if your air meter (be it Vane AFM or HFM/etc) maxes
out inside the operating range, you are hosed good.

Motronic needs exactly three things to calculate LOAD.

1) A signal from the air meter, normalized to "Q" airflow in kg/hr

2) A measure of current engine rpm "n"

3) A programmed injector size constant "Ki" (K sub eye)

LOAD aka Tl (Tee sub ell) is calculated as:

  Tl = Q / (n * Ki)

LOAD is not just a representation of cylinder filling, but the
theoretical Injector Time Open (Ti, Tee sub eye) needed to reach
stoich (Lambda= 1) with the current injector setup assuming that
the motor is "perfect".

Which it isn't, hence there are fueling tables which are used as
multiplicative corrections to LOAD to reach the actual Ti.

Hope this clarifies.

Jim Conforti


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