EFI and leaded gas

[Johnny]

At 04:31 PM 11/29/95 CST, you wrote:
>
>>If leaded gas is death to O2 sensors, how can the EFI run in a closed loop
>> mode?
>
>Of O2 sensors, I use a heated NTK sensor... mounted into slip fit tube
>that slides onto the tail pipe once the car is warm. Quick blast up
>a few hills to get an idea If I had a lean condition under load.
>
>Back to aircraft...
>For LONG TERM measurements, it would be worth while to monitor the
>Exhaust gas temp with thermocouples (common for aircraft) to get
>an idea of the operating condition. Fun part with be to slightly
>change the mixture at cruise, recording all the paramters. This
>should giv you a baseline reading. While O2 sensors are quicker
>to respond, you could develope a "cruising closed loop" system.
>
>CAVEAT: I haven't done it, just thought this would be ONE way of
>attempting such a beast.

I have found that while this can work, most pilots can't fly without the
mixture knob to play with anyway... so I have included a dashboard (called
the panel in an airplane) mixture trim. Just a pot that trims the curve. All
the way clockwise for the normal, preprogrammed curve, then turn it to lean
accordingly. Most pilots fly off the EGT or else adjust by leaning to peak
power. Even if they didn't need to do it manually, they still would want to
be able to (it's a pilot thing). The trim knob makes it easier to compensate
for altitude as opposed to modifying the curve with programming, which I do
anyway.

I have yet to get the laptop and the flying testbed together all at once. As
soon as I do, I will be able to record exactly what the lean for altitude
modifier has to be. The dinosaurs will still want a mixture knob to play
with though.

-j-