Leaded gas and O2 sensors

[kachok25]

OK we all know that leaded gas is not good for O2 sensors, but dont some of the racecars and aircraft that use it have O2 sensors in them? Or is there some other means of controling the air to fuel ratios? Is there any way I could setup an ECU to where it would not need the feedback from an O2 sensor, but just opperating off of the air mass sensor and the intake pressure sensor. That could theroeticaly give me all the info I need for proper fuel managment ASSUMING that everthing is working properly. BTW what is the highest octaine leaded gas out there I heard they used up to 150 octaine but I don't think they make that stuff any more, that was just for the aircraft during WWll.

[MagicRat]

Gasoline piston-powered aircraft usually uses surprisingly primitive technology. This is because its very expensive to get new technology approved for aircraft use. Therefore, many small, private planes use carburetors, or mechanical FI and not EFI, because they are basically using 1950's technology and systems.

New small plane development is usually directed to the commercial aircraft market, where turboprops are used. Since they basically use jet engines to turn propellors, they do not use O2 sensors.

Very small planes, ultralights and custom made kit planes fall through loopholes in the aircraft approval process. Often they use variants of autmotive or recreational engines, which use unleaded pump gas anyways.

Lots of early EFI systems, mostly used in some European cars int he 60's and 70's did not use O2 sensors. They used mass airflow, throttle position, engine temp and revs to determine mixture. This worked okay, but was not too accurate, especially for use with cats.

[kachok25]

What about racing cars? I am sure some of them use leaded fuels and EFI don't they?

[curtis73]

Yes, but they don't use O2 sensors. Even if they did, I would assume they could be developed to work well with leaded gas, but cost an arm and a leg... which makes them unsuitable for the street.

Even if they ran leaded gas with regular street O2 sensors, I'm sure they'll operate fine for the 500 miles of the race. They can be replaced every race, which is another reason they wouldn't fit in the plan on the street.