DarinS4Turbo

It is not running closed loop.

DarinS4Turbo

I mean c'mon - the ECU just closes the wastegate to compensate and overspins them to oblivion? As the original poster said, that would be pretty stupid of Bosch, wouldn't it? I even recall Brett @ APR mentioned this in a post - in the event of a boost leak (torn TBB) Bosch already thought of this scenario - the system will protect the turbos (limp mode) before damage can occur. The data I've collected supports/explains that.

VonK :: Retired

.... there would be only one fixed waste gate position except for limp mode. That could be achieved by a simple solenoid with adjustable preload spring. Why have this variable bleed valve to begin with. The Wastegate doesn't only come into play at WOT and high revs. If tuners take your suggested approach, no wonder they wind up with drivability problems.

DarinS4Turbo

I didn't say it was fixed in that regard (duty cycles can be 45%, 85%, all over the place depending on the conditions and driver input). What I'm saying is the values programmed in, for the conditions, do not adjust or compensate based on the boost sensor. The link below is just an example of this data and proves my point. If you do a WOT run and graph your N75 duty cycle, it will look the same regardless of any deviation in the boost sensor reading from expected (unless you trip a DTC and it goes into limp mode or 0% duty cycle!)<ul><li><a href="https://forums.audiworld.com/s4/msgs/1068857.phtml">https://forums.audiworld.com/s4/msgs/1068857.phtml</a></li></ul>

DarinS4Turbo

data which I have posted, and you still haven't addressed even though it is staring you right in the face.

If I recall, someone has also been preaching to us that modifications to the stock airbox and filter are worthless, yet data continues to come in that proves otherwise.

DarinS4Turbo

from the expected boost value, the purpose of which is to set DTCs and/or go into limp mode if that deviation is too great.

DarinS4Turbo

Good night :-)

VonK :: Retired

Your data just seem implausible in light of what the ECU was designed to do. I have frequently misinterpreted data, only to find that I made a mistake, used faulty equipment or had a faulty test article.

How many tests have you run on how many different cars to verify your results?

Cheers,

Harald :-)

zapco98

yielded running the same boost for the same duration through the RPM range. Boost would sometimes spike to 20psi with K03s, but never ever held it to 6000rpm. Infact, its funny that the motronic ECU even adapted correctly to the added airflow and maintains an identical A/F ratio that it did on K03. An even 12.5 it looks like. Further more you can add a manual boost controller, and not throw a DTC with the ECU (Per article on Autospeed). I think Darin is right as it being "Expected vs. Actual" isntead of "Requested vs. Actual". I have seen the so called "Requested" at 1.4bar @ 6000rpm with K03 software - How did the software automatically change its values? I can also adjust my N75 up and down at will, and run from .8bar of boost, to 1.4bar of boost, with no DTC's either - How does one explain that?

VonK :: Retired

.... but is an adaptive calculated value based on multiple sensor inputs, much like the adaptive A/F ratio. I've seen logs that showed the "actual" boost disobey the "requested" boost without DTCs.

BTW was this a stock K03 ECU?