Re: was resistor in the O2 loop now AFM flap shennanigans

[Rob Ellis <aellis@xxxxxxxxxxxxxxxx>]

>  I don't think these flap shenanigans will get you any benefit. When
> the motor runs in closed loop mode, it watches the O2 sensor for the
> results of the inputs.  If the AFM were to change its behaviour, the
> ECU would merely adjust in a short while and you'd be back to normal,
> mixture-wise.

I was in doubt when I first heard about it, and I'm not 100% sure why it
works (read my previous post for a bit of the "theory"), but it does.  I
have verified the effect using an exhaust gas analyser AND using an Air
Fuel mixture meter.  Adjusting the flap tension seems to change the "base"
fuel mixture, even at idle.

If anyone has a concrete idea why this appears to work, despite the O2
sensor, please let us know.  Maybe the signal from the AFM also serves to
set the Lambda value that the ECU expects to see from the O2 sensor???

>  As for full throttle operation when the O2 sensor is ignored by the
> ECU, the AFM flap is fully open above 3000 RPM or so.  Adjusting the
> flap spring pressure a little will do nothing for you in the "fun
> zone" of RPMs and throttle.

I agree, it will only affect non-WOT mixtures.  But I don't think the flap
is truly "fully open" until 4000-4500rpm... but I haven't tested this yet.
It's hard to check while I'm driving :)  The signal from the AFM could be
monitored while driving to verify this.

I also agree that this mod probably won't get anyone very far.  But,
someone may benefit, so I guess it's worth mentioning.

Rob

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