[Diy_efi] WB free air calibration

[Shannen Durphey]

After seeing some numbers this past weekend, I know that Gar's "knock
'em down and run 'em over twice" marketing plan needs to be revised if
he hopes to come anywhere near the number of DIY-WB's sold.  People
are hooked on the DIY sensor.

Just some thoughts here.  It would be a bad idea at this point for
anyone to apply for financing for a business selling and manufacturing
their own wb o2 meters.  It's gonna hurt every time another one of
these homebrew babies gets sold.  I guess if I had were selling meters
at twice the cost and less than half the volume of the DIY unit, I'd
have to do something to make sure mine looked better to the general
public.  I'm not so sure that putting the chief engineer in charge of
namecalling is the best way to do things.  Then again, I'm not trying
to sell my meter over someone else's.

But if the predictions of doom and gloom are at all correct, it won't
be very long before people start showing up on the list and
complaining of engine failures.  An incorrect AFR on a seriously
abused car doesn't take long to show itself.  I've seen plug
electrodes burn off in seconds when nitrous is involved.

The diy meter has been in the general public for over six months now,
yes? 
Shannen

Garfield Willis wrote:

> The errors with these two 'dweebs' using this large a spread of sensors
> are HUGE. Sometimes as much as 1.5AFR, and that's ignoring EBP errors.
> Partly due to the fact that the Cal R circuitry is just plain WRONG in
> the design (which is why the free-air values are all over the place),
> and partly due to the fact that the pump control circuitry used causes a
> hysteresis effect whenever you quickly go rich or lean across stoich,
> which throws the transient results especially off by as much as 1AFR.
> Yes, one whole AFR. I have it on good authority that the dweed-O2 Cal R
> circuitry was 'reverse-engineered' based on measuring just TWO sensors.
> Yuh, good plan. I could quote the person involved, who didn't know he
> was communicating with us at the time, but I wouldn't want to embarrass
> him. :)  I even have drawings and explanatory notes; we do our intel
> homework.

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