How many of you run 87 octane fuel?

[nomad]

+2 HP falls within the statistical error range for the dyno runs...

[mkodama]

Blah blah blah blah how can an air temp sensor determine your altitude? If an M20 has a sensor for altitude why wouldn't our engine?

No, haha, of course a temp sensor can't determine altitude.  It's that flappy air flow meter that compensates for altitude.  The less dense air at high elevations will move the flappy meter thing less, and slightly less fuel will be injected since there is less air.  Make sense?

For all I know, the M42 and later fuel injected M20's had a second barometric sensor for continuous altitude correction.  I don't know but I have yet to see one listed in the ETK.

But yeah, the M42 is pretty good right from the factory in my opinion, no reason to start unplugging sensors.

[EN318isPDX]

No, haha, of course a temp sensor can't determine altitude.  It's that flappy air flow meter that compensates for altitude.  The less dense air at high elevations will move the flappy meter thing less, and slightly less fuel will be injected since there is less air.  Make sense?

For all I know, the M42 and later fuel injected M20's had a second barometric sensor for continuous altitude correction.  I don't know but I have yet to see one listed in the ETK.

But yeah, the M42 is pretty good right from the factory in my opinion, no reason to start unplugging sensors.

Thanks?

[christophbmw]

Between the TPS, Barn door airflow meter, Air intake temp you can get a pretty decent altitude reading. But then of course it will not compensate for different pressures due to weather and climate. Im pretty sure it is probabally set in the DME for a standard pressure of 29.92 at sea level. Our cars are not that great of performers at higher elevations. But then again no car is. Im used to flying airplanes where the the pilot can set fuel mixture on the fly (but then again cars where not made to have drastic changes in altitude, in short time;)).

[mkodama]

Between the TPS, Barn door airflow meter, Air intake temp you can get a pretty decent altitude reading. But then of course it will not compensate for different pressures due to weather and climate. Im pretty sure it is probabally set in the DME for a standard pressure of 29.92 at sea level. Our cars are not that great of performers at higher elevations. But then again no car is. Im used to flying airplanes where the the pilot can set fuel mixture on the fly (but then again cars where not made to have drastic changes in altitude, in short time;)).

Many new cars compensate for altitude. Like, even the EFI controller I just built has an option for contnuous barometric correction. I'm seriously itching to put that controller on an m42!

[Birdman16]

The previous owner of the car ran it with the crappiest octane he could find and was too cheap to put premium in it.  It gummed everything up in the engine and i had to replace and clean a lot of internal parts because of it.  Once in a while is OK but don't do it forever.

[tjts1]

The previous owner of the car ran it with the crappiest octane he could find and was too cheap to put premium in it.  It gummed everything up in the engine and i had to replace and clean a lot of internal parts because of it.  Once in a while is OK but don't do it forever.

How did you establish cause and effect? What parts exactly were "gummed up"? How often did the previous owner change the oil? What kind of oil did he use?