It is exactly the same as you said. The process you described does not exist on this car. No cars actually increase fueling on overrun, the ones that pop and bang simply do not cut all the injectors all the time and use a very late ignition angle.
On this particular engine the cylinders are cut at the highest possible speed that does not cause a jerk and are phased in the same way.
They are cut completely. The injectors are fully closed.
Again, it is not possible to make it run above lambda 1 in closed loop without modifying the code in the ECU, especially if you want to do it only on some rpm's. Even then, as I said, the difference would be <1%.
I have tuned this very engine. I have put it in a different chassis. I have strapped a supercharger to it, and I have tuned the said supercharger to perfection.
I have something you do not - I have actual experience with this very engine, and this is why I am replying to this topic in the first place. Your theorycraft is going nowhere, because you could not be more wrong. You have no experience with this engine and you have very little experience calibrating VAG gasoline control units, because what you said is simply the exact opposite of what happens in reality.
i picked up a procharger d1sc kit for my 4.2 bfm engine in a d3 a8l. plan on slower s/c rpm around 4in or 4.5in pulley on the d1sc. should be good for 400whp+- with a intercooler and meth injection. is there a easy way to add a map sensor with the original ecu? or would just the maf sensor be plenty speed density tuned?
@prj what supercharger did you use? also what power were you able to make from a oem bfm engine with the supercharger? if you still have some pics post them up id like to see them and hear your experience