fuel mixture (AFM, O2 sensor)

[Rob Ellis <aellis@xxxxxxxxxxxxxxxx>]

> From: alex.fadeev@domain.elided
>
> All this tweaking of the 02 sensor and AFM is a fool's way of blindly
> futzing with your car's air:fuel mixtures. In the same single digit IQ
> "mod" range as dumping arbitrary larger fuel injectors, arbitrary
> increasing fuel pressure level, swapping AFMs or screwing with their
> output.

I hope that no one would make any modification "blindly".  In fact, I
would urge anyone who "futzes" with the AFM, O2 sensor, or any other fuel
component, to check the results with an air/fuel ratio meter, an exhaust
gas analyser, or if possible, a dyno.  It's important to know the results
for YOUR car, otherwise improvements can't be made.

Also, I hope no one would make "arbitrary" changes to their car.  Each
person should research available information, make their own decisions,
perform calculations, and compare these with actual results.

> Depending on the year (and DME version), the ECU stores numerous (tens of)
> engine air:fuel:RPM maps depending on intake air temp, engine temp, full
> vs. part throttle, etc, etc, etc.
> Messing with one input might fool the DME into arbitrarily enriching the
> fuel mixture across _all_ of those maps. There is no way in hell it is
> beneficial for all of the maps under all of the conditions.

Agreed, however, we've already come to the conclusion (through polite
discussion) that these modifications are only good for non-WOT situations.
We should also assume, that we are trying to modify the fuel mixture when
the engine is warm (not in open loop).

Within these restrictions (closed loop, non-WOT), ALL of the maps (at
least for my car) are set to provide a fuel mixture that is at or near
14.7:1 which does NOT provide maximum power.  Therefore, if someone can
find a mod (be it "free" or expensive) that allows their car to run a fuel
mixture closer to the power maximum, then more power to them (pun
intended).  Again, I'll stress that the result needs to be verified via a
proven method (no arbitrary changes here).

> Doesn't mean that some internet monkeys would not advise you to try these
> 'free' mods.

No one is advising anyone to do anything here, we're just sharing
information.

Alex, If you don't agree with the information we share, please, join the
discussion, and enlighten us.  But it is not necessary to use words like
"fool" or "monkeys", or to make claims about the IQ's of others.

Rob

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