I think, if I understand this correctly, that this is the key bit here.. (for me at least) Measure... IAT, EGT, yep I get.. Measure Load tho? (from ecu? a calculated value)

non egt cars cannot be tuned in this way is my suggestion.. No way would you want to rely on downstream lambda heater temps for tuning against egt's.

Where a GT3071 is "small" to you, what level of power are you tuning via egt's etc for?  Tune to egt's I get, and understand is whats done on alchy cars, muchos bhp engines etc, but in context of 1.8t (me and tuffty) I am trying to see if the context and methodology still applies.

thx

Just because someone doesn't agree with you DOESN'T mean they don't understand your point.



Now this I don't see your point. KFLBTS has a Act Load axis. So, it doesn't just enrich via RPM only. Factor in the load axis and the map can handle low verse high gears.

cause your lamfa was not difinded correctly .
->http://nefariousmotorsports.com/forum/index.php?topic=1272.msg11844#msg11844

Interesting... changed LAMFA on an Leon Cupra R project I have.. set it to the following from page 3 of the thread you linked too(1ML906032A  -> LAMFA: 0x81C98A, X_AXIS: 0x81C97E, Y_AXIS: 0x81C96E)

Swapped the X axis from 16bit HiLo to 16bit LoHi and get a load axis from 50% to 100%... you are saying this is now correct and the 0% is wrong?

Anyone else care to shed some light on this? I also checked a G box file (8D0907551G  -> LAMFA: 0x81C390, X_AXIS: 0x81C384, Y_AXIS: 0x81C374) and did similar to pull LAMFA in to this revised layout....

Must say I am a little confused about this now... fuelling has always been right on mine before this revelation...

<tuffty/>

Just something quick to add to this...I've heard said several times in this thread that fueling is not RPM dependent. This is generally not true. In most occasions for a given load value, your lambda value should be getting richer as RPM increases. I think maybe the misconception comes from thinking of the combustion in the cylinder as "engine domain/engine synchronous" (perhaps this may be partially true at low speeds where the turbo is operating in the "pulse" regime, but not at higher speeds when it is considered to be in "pressure manifold" regime.)  In addition to considering combustion events in cylinder, you must remember that as RPM is increasing the turbo remains the same device (obvious, but important to consider in this case). In turbo applications, the lambda value for maximum output is dictated by the maximum allowable turbine temperature. As RPM rises, even if you are holding cylinder filling constant, the time averaged mass flow across the turbine is increasing. (In simple terms: the engine is refilling its charge roughly the same amount on each intake stroke, but the turbine size is of course not growing) This will generally lead to a higher pre-turbine pressure and as they are linked by gas laws, the temperature as well. In summary: for a given filling where timing is operated at approximately MBT, mixture must be enriched to decrease the pre-turbine temperature to below its operating maximum as RPM increases.

A lot of people spend time saying ".85 for max power" or whatever, but you have to realize the driving force of that. It is largely not in-cylinder combustion (for this case, it is generally .93-.95, or 1 if you have perfect mixture and flame propogation). The .85 becomes necessary at full load mostly because of turbine temperature. Increasing the fueling allows you to increase the load, and the increased load that is allowed by .85 or richer mixtures is what allows you to make a torque increase over what it would be at .93-.95.

Load is cylinder filling. Not understanding this, is not understanding what Motronic is about.
ME7 has an EGT model. If you don't have a properly calibrated EGT model, then you can't use EGT to fuel off. When the EGT model is properly calibrated, it is usually pretty damn accurate.
Let's just say, GT30R+, but this is irrelevant, I was saying it tongue in cheek. You'd have to screw up pretty bad to blow up an engine on ME7 anyway. 200hp/litre is baby power for it.

Nope. My point is you can have 700 EGT at 6000 rpm in 3rd, or 900 in 6th at same load. Is the fueling need equal? Please do tell.
If you map via RPM and LOAD as done on all old ECU's, you must run not enough timing and too rich in low gears, so that high gears don't knock. That's why I said tuning is not steady state, and tuning is not 3rd gear pulls.

You basically just said exactly what I have been saying. Except RPM does not factor into the equation.
The correct measurement is combustion chamber temperature and exhaust gas temperature. The higher the combustion chamber temperature gets, the lower the knock threshold. The lower the threshold, the more timing is retarded. The more timing is retarded, the more EGT rises, as more energy is converted into heat. The fact that it occurs with higher RPM is logical, but when you have the ability to fuel off of combustion chamber temperature directly, it is much better than mapping based off of RPM, which is just a side effect of things.
The reason older ECU's are mapped via RPM, is because they don't have an EGT model, they don't have EGT measurements, there is no way to model the combustion chamber.

But the actual req fuel for best power constantly drifts, and if timing is advanced sufficiently, then it is almost directly proportional to EGT.

It's good we have discussions like this though. Perhaps it will remind people, that the ability to change a few numbers in the ECU and the ability to understand the physical processes inside an engine, and understanding *why* every change is made are completely different things.