Macster

The DME adapts constantly as various inputs change. This is quite obvious when one starts a cold engine and it idles and warms up. At no time is the engine improperly fueled.

I'm not the only one to have done this but I can say from my experience driving my Porsches in all kinds of driving conditions in all kinds of weather from near zero temps to triple digit temps from a few feet below sea level to nearly 9K feet above none of my Porsches has ever been caught on the wrong DME foot so to speak.

Another technique to observe the DME adapt is to while the engine is idling remove the oil filler tube cap. This creates an air leak and while the engine initially reacts the DME in just a moment sorts out the fueling. This is at idle but at higher engine speeds the adaptation happens even quicker.

Yet another example though one can't observe is when the knock sensors detect the signs of detonation. The DME adapts so quickly that the harmful detonation never occurs. Thus these engines can run very close to incipient detonation for thousands of miles with no harm.

No slow to learn DME would result in that kind of engine longevity.

While the quarter mile guys assign the 1st run to the DME, the DME doesn't need this.

Under hard acceleration the DME goes open loop and then uses fuel/ignition maps that are designed to meet the torque demand of the driver.

So whatever the DME has learned isn't used in this case.

The benefit of an extended run at "speed" is the valve and combustion chamber deposits get removed -- washed or burned away -- over time and combustion improves.

ArniO

Macster - another good, informative post. Thanks, dude

perryinva

Yes, that makes solid sense, thanks. I know it had to do with the load on the engine. Obviously 5k rpm in 4th is under a lot higher load than 5k in 1st, 2nd, or 3rd, so there would be elevated combustion temps from the increased flow of fuel, and hot exhaust gases. I like Gonzos take on accelerating away. Too funny.