[wookwook]

ok good news. I was gonna say, i looked around and there was note some where they said it may to 2 rounds of uploads for A8, i assume one for the TCU and one for the ECU.

The slow to close TPS. Its a thing with the engine. One thing I appreciate the M6 for. You jam the clutch as in a course run and the engine keeps up the RPMS under the high load and sudden decel. After I work out my current projects I should come back to it and see what if anything affects it. I 'dont' think its a blow off through the intake right now, since the Jacfab is extremely efficient at wasting the boost. Its still a mystery, to me too. All I can say is eventually as the thrill wears down, you wont be driving as aggressively and it wont be as much of a problem usually. Small consollation I know.

The engine momentum is a 'thing' and several have reported it. It's not flywheel or anything mechanical b/c it affects both A8 and M6, its in the ecu RPM/TPS ramp down logic, i am pretty certain. That the track I am taking for now.

* - Actually now that I reflect on it, someone suggested its a burn off strategy for waste fuel and air as to why the delayed sense of engine throttle down is, its an emissions strategy and its magnified because of the underlying linkage in the tables are altered from stock now, it seems we haven't found the magic bullet to smooth that out yet. yet.... its just tied to the increase in torque and there are a lot of potential links that contribute, but may not necessarily be perfectly visible in the tables. Its like trying to stop a barge now, as opposed to a fishing boat. Someone will find an effective link someday. I think it was brought up in the Randy Probst post a while ago.

So turbo upgrade. Not to sell short on 'tunes' that shops spend hours and dollars developing, so I am careful not to delve far into the tuning needed to go into the 'advanced' tables to use the increase torque of bigger turbos. Suffice it to say it needs specific reads from histograms that have special math calculations and certain table settings temporarily staged to lock things like extra fueling to read the adjustments.

In a nutshell, its an experiential re-calibration based on your setup. as in actual dyno reads. It can be done on the street, yes that it's true you don't Require a shop, but for most people its the way to go. Its a back and forth kind of involvement that STM said before. You wont blow anything up if you drive home on a bigger turbo, but wont gain anything because no growth/room for power was sent to affected the tables yet.

It aint your grandfathers Oldsmobile, taking from the old advertisement, remember them? Yeah. Its all very very tightly controlled for emissions and MPG now. All computer logic. GM makes it easy to get basic tweaks to a point, but the hard core stuff like turbos, requires more thought and skill to pull it off well.

sorry for the book, just my musing.