I'm a little new in this platform, and after finding four unique forums that cover the car I just bought I stopped looking. There's only so much time in day. I don't know all the politics and don't care. Since this is Tony's thread and his testing on his car he can take it where he wants. I have noticed Tony is running out of places he will post, and I hope he will always have a voice because the information and things VTTO builds, sales, and just shares are golden. Also some people need to realize that just because someone is on the leading edge of something doesn't mean they have all the answers, and if they can't give you all the answers that doesn't mean they are lying or hiding something. If you think they are then prove it, especially when the person being questioned has a history of not handling perceived criticism very well. I've seen this scenario many times over the years. Some racers who post a lot are very fast and really don't know exactly why, and I'm not claiming that anyone here is dumb just that some should relax and strive for answers instead of expecting one person to be able to spoon feed everything to them. Nobody has all the answers, but some have a ton of knowledge and results and share the answers they do have, for that I am very thankful. This saves me a lot of time. So thanks to Tony and Chris for that.
So anyways here's something I wrote last night I will re-post here as well. I didn't steal this from BB. I wrote it, so here's a plausible explanation for some of the low end gains besides just complete combustion (as imagined by me).
I was reading a thread at lunch yesterday and thinking about this. Here's what I came up with that seems interesting. First I must admit I was amazed when I learned that the N54 and several other new direct injection turbo platforms like Ecoboost, and Skyactive did not need nor utilize a Mass Airflow Sensor to directly measure the volume of air the engine is consuming at any given moment. These new wide-band Oxygen sensors must be really fast and accurate, so much so that the fuel injection can just rely on much simpler sensors like Manifold Air Pressure and temperature compared to tables such as VE and then make all corrections after the combustion event via the wide-band reading. And then we can just go about doubling boost and changing everything such as cams and intercooler and the damn thing still works, even responds to this. For someone who graduated from programmed fuel injection with O2 correction to Mass Air this step form Mass Air to programmed with wide-band correction seems backwards. That it works so well blows my mind. But this causes one to re-think things a bit. With a MAF system at WOT fuel is added based on the load calculations and O2's are largely ignored. It's programmed to provide a rich mixture to provide enough fuel to easily light and cool down the combustion chamber to prevent pre-ignition, detonation, and lean mixtures. But if there are any misfires at WOT that un-burned Oxygen just passes by the O2 sensor, lowering the voltage by some amount but effecting nothing related to air/fuel ratios. But on this system, the N54 and others like it, that un-burned Oxygen will have some effect on the wide-band reading that could effect the immediate air/fuel ratio. Now A/F sensors do detect rich mixtures, so are they able to process the un-burned HC's at the same time and as effectively as the Oxygen? Good question and I'll have to go read up. Not many of the classes I go to have instructors that think about this much less try to incorporate these hypothetical's into the courses. Most times my questions make them think and realize things they hadn't considered. But what I'm trying to say is this. If you have a considerable amount of misfires under WOT say 5-10% when everything else is optimized or 30% if you run stock gaps. Therefore you have significant amounts of O2 and HC's going past the sensors. How does this effect the fuel injection's perceived A/F Ratio and thereby it's corrective action to adjust said A/F ratio? If the raw O2 has it's way the A/F sensors are going to report this and the DME (in the BMW case) is going to command more fuel to try and bring the ratio back into target numbers. This extra fuel above what is actually optimum for max power will therefore reduce power. So if this is happening, and one comes along and upgrades the ignition system to the point that these misfires are eliminated now all A/F feedback suddenly becomes a lot more accurate. So in this scenario fuel would be reduced because it's no long trying to cover raw O2 in the exhaust. Overall combustion heat, and therefore combustion pressure goes up again. This again drives the turbo turbine harder still, again more power from more power. Like Tony said, one efficient engine. The better it's working the better it works, sounds corny but that's how I view it.
Now I may be a little off here, I'm not exactly sure how these wide-bands will read the results of mis-fires, which if any way the readings will be a skewed. I'm a little biased because for years, well decades now, O2 sensors just reacted to Oxygen and had no clue about the Hydro Carbons bumping into them. So I tend to think readings will lean out. So while I fully comprehend that wide-bands are excellent at processing the exact ratio of com-busted air and fuel by-products, I reserve that they may no be so good at raw air and fuel thrown into the mix. So if there's someone on here who knows about this better than I do yet please do tell. I'm just trying to explain this recent dynamometer test to myself as well as anyone else like you guys doing the same. With my theory the A/F graphs may look only slightly changed, but they may actually be a lot more accurate than before.
Vernon