O.k. So I just compared the 265 bhp S4 maps with the 380 bhp RS4 stock maps and am seeing very little difference, certainly not enough to suggest that Audi are using KFMIRL and KFMIOP to increase output.

TTQS

i believe the goal in tuning the Torque Model is not to increase output but rather to alter the manner in which output is delivered and to keep Torque Monitoring from trying to shoehorn our 500 hp into a delivery scheme designed for a very refined 250 hp.  In this way we can program the personality of the vehicle as we like.  We all have seen, over the years, quite a few tunes that attempt to alter the personality of the vehicle by requesting incresed loads sooner in the rev band - with varying degrees of success.  This said - we definitely need to alter at least the last 2 columns of KFMIRL in order to achieve the power levels desired in a STG3 or greater tune.

Here are the stock tables for S4 and RS4 for us to examine.  Notice that the RS4 maps do request more load sooner and a greater peak load in KFMIRL and that the x-axis in the RS4 KFMIOP is shifted upwards to reflect this greater load for a given %Torque request.

RS4 KFMIRL


S4 KFMIRL



RS4 KFMIOP


S4 KFMIOP


Now is a good time to think about the purpose of the Torque Model in Motronic. Here is how I am coming to understand it --

In a turbocharged vehicle the available torque varies wildly across the rev band usually with a steep torque curve which increases greatly over just a few hundred RPM.  In a traditional non-torque-managed scenario the driver compensates by applying greater throttle at the start then anticipates the onset of boost and reduces throttle input accordingly.  This may suit an enthusiast but would be considered unrefined and unacceptable for an average customer, especially in the luxury segment.  This is a particular problem in vehicles capable of more than 300 lb/ft of torque as the driver will need to carefully modulate the throttle input in all dynamic scenarios that involve load change in order to avoid violent bucking and surging with increasing loads.  ME7 addresses this particular shortcoming of turbocharged engines with the Torque Monitoring function which manages the varying engine output of the engine to match what the driver is requesting via throttle input by way of modulating ignition timing, throttle plate angle and boost.  When revs are low and engine output is low relative to what the driver has requested via the throttle ME7 will open the throttle further to more quickly achieve turbo spool and meet the requested torque.  As engine output sharply rises ME7 will close the throttle as necessary to achieve a linear power delivery, previously uncharacteristic of turbocharged vehicles.  As such, the S4 in stock form has a generous torque plateau across a broad rev range and was universally praised for its smooth power delivery.

Understanding this becomes crucial when one wishes to modify the engine for power output well beyond original levels.  ME7 was tuned by Audi to achieve a particular level of performance AND refinement.  This benchmark level of power and its DELIVERY – the target that ME7 is trying to hit – is defined by the ‘optimum’ tables.  When we attempt to ask the engine to produce more power in a more aggressive manner sooner we must also take into account the manner in which ME7 was programed to deliver this power - or what it considers optimum.  If we modify Load Requests but fail to appropriately alter the parameters that govern the rules of how it is to be delivered then the result is ME7 attempting to deliver STG 3 power using a delivery method designed for the refined delivery of ½ the power. 


when examining RS4 maps i have to remember that the RS4 was quite refined and, while powerful, was fairly conservative given its hardware. 

My goal, personally, is to understand the model enough to 'turn up the wick' not only at WOT but througout the rev range, while still maintaining the refined nature of the power delivery.  As it stands now - when I do turn things up, Torque monitoring is spoiling the fun in a variety of ways (and as an aside - I'm beginning to believe TM is responsible for the timing oscillations in very fast S4s).  If I disable TM, I suspect the throttle will be wild (it was in 1.8t cars i've driven w/o TM) and this get's old in a daily driver.  I'd ideally like to tell Motronic how I'd like the power delivered and let the TM smooth out the edges.

Case closed.

Berttos, thanks for the analysis. I believe you are SPOT ON. Also, I believe you are right about the timing oscillations being the result of improperly calibrated TM parameters. However, even WITH req torque well above act torque, I still see timing intervention. I have yet to discover the source.

You better stop by my booth at h20 and say hi. 

For the sake of contributing the best that I can, would it be possible for somebody to send me the KFMIRL / KFMIOP / (misc.) including the Axis-Limits for both the S4 and RS4?  I could do a precise MATLAB interpolation to get the desired "reverse-mapping" of the RS4 setup onto the S4's tables.  Of course, if thats what we wanted...  From what Berttos has suggested, even the RS4 torque control is too buttery?

Thanks to BerTTos again for top notch analysis. After posting previously, it became clear that KFMIOP/KFMIRL are indeed for tuning the torque delivery profile, not the output magnitude. I think I'm happier about that than I was before, which is good.

I have an RS4 OLS file which I will upload when I get back. All the parameters are fully defined just not grouped together into the funktionsrahmen modules.

One exercise I was going through which I felt would be informative was to trace the torque model through the diagrams from KFPED to throttle angle/intake manifold pressure, identifying the input and output variables and maps involved at each step.

I got about 8 steps in when I got confused at FUEDK. That's when BerTTos posted up his original question. I'll continue with it when I get back home then post it up in a separate thread so we can all pick over it and come to overall conclusions about where the tuner should intervene and for what purpose.

My present understanding is that LDRMX profile should be altered to increase output under WOT conditions but I'm not sure about increasing torque under part throttle.

TTQS

I have had trouble locating axis maps this way at times, how do you decide the equation values?

yeah i was being a moron, I failed to just check the equation of the associated map.