That is a misinterpretation of the words I said. You wouldn't expect someone to become a master mechanic from reading an owners manual.
In case you are curious about learning more I will document some of the things that are misunderstood or misrepresented in your guide. Maybe it'll help someone and maybe it'll spark curiosity in others. Anyway there are numerous errors, I understand that you said you want proof of operation from VW or Borg Warner but frankly most of the info about how these systems work simply can't be figured out from reading marketing material that is posted on the internet. Here are a few:
There is no 'worst case scenario' for any LSD. A car on level ground with all the wheels pointing straight ahead with no grip/torque difference between the driven wheels is not interesting. In this case the differential solution is irrelevant. In this specific case (no grip difference between driven wheels) a force to the input shaft of a locked diff, or an open diff, or a VAQ, or a wavetrac the end result is the same: the wheels spin at the same speeds when any power is applied.
The real interesting case for a differential is when considering a car navigating a corner, an ideal limited slip differential is one that redirects as much power from the less loaded wheel to the more loaded wheel without putting either wheel into slip. This is challenging because the wheels have to travel different distances. Any limited slip differential acts by applying a braking torque to the wheel spinning at a higher velocity and an accelerating torque to the lower velocity wheel. The real challenge is getting this just right such that as you navigate the corner you don't put a wheel in grip into a slide by either braking a wheel that has traction or accelerating a wheel that has traction too much that it starts sliding--both of these will result of loss of stability in the front end. The benefit of getting it right is more forward drive on power and greater chassis stability on deceleration. An overly weak LSD you might have poor drive out of a corner where an overly strong LSD will upset grip experienced for the entire drive axle. No limited slip differential solution is always going to provide a correct solution here. There is no magic spend money button: its all comprises and fine tuning
This is simply not true. There is no minimum amount of torque imbalance between the driven wheels to lock up. Anyone who has played around with obd11 logs would know this. From any stop the car actually applies current to the clutch pack. Sitting at a stop light with the wheels at a stop the axle is always locked and as soon as you take off from the light the car starts unlocking as appropriate. People who have done data logging will see that there are predictive algorithms at play which also lock the wheels based on throttle and steering angle before any difference in wheel speed or slip happens. Figuring out exactly how these predictive algorithms work isn't something you will ever be able to do by reading the white papers. If you are really interested you are going to have to reverse engineer this.
XDS+ is not required to get the VAQ to work. Anyone who has done datalogging with various XDS systems enabled would know this.
This is not true. See our previous discussion. This was a result of you confusing the differential in the SEQ cars with that of the DSG cars.
Its not a good look or good form to quote papers out of context without sourcing the name or author of the paper
Wavetrac is clear to not call their devices lockers. If you look at the friction area on the wavetrac you can probably get an idea of how much power can be transferred in the zero load case. Also, plenty of videos available of wavetrac not being able to move the car with one wheel in the air. This doesn't necessarily make it a bad limited slip differential.
You have confused the engine torque applied at the flywheel with the torque applied to the clutches of multi-plate differential. These are not the same thing and operate at different leverage ratios. There is no relevance between the two as suggested.
These are separate systems and don't talk. You don't effect the operation of the FDL by changing XDS settings it still responds to the same inputs in the same way. This is clear from data logging.
For the same speed, G load, steering angle, yaw, and wheel speeds it will behave exactly the same
The fact of the matter is that electronic controlled multi-plate clutch differentials have numerous advantages over the classic mechanical only clutch and gear type LSDs. Not being able to directly sense torque is also a potential drawback (that being, said who knows, the center diff in the Subaru STI previously had both a torsen and a e-LSD in one package and now its just the e-LSD with the torsen still existent but mechanically disabled since 2018). We are seeing in modern high performance sports sedans and sports cars a big movement away from mechanical LSDs. Whether we like it or not these solutions are the future. Among about half of the GT4 racecar field you have electronic diffs. If you go buy a new GT3 RS you have an electronic diff. These e-LSDs can evaluate more relevant information that will never be considered by a mechanical only solution and are far more tunable in real time for tire wear and track conditions. Things like yaw, wheel angle, and G loading are all relevant in terms of deciding how much to lock. In terms of the unit in this car, I have not seen any empirical data on the VAQ vs any of the mechanical only solutions but I would love if someone has collected any data to show where each system shines. I have also seen reports of people complaining about overheating but haven't seen anyone actually prove their issues were diff caused (and not tire), again I would love to see this info because it contradicts my experience.
To this day these units continue to be used in IMSA IMPCC 2hr-4hr races. In europe they are used in longer endurance races. If you look at the tech video FCP euro did on
old RS3 LMS DSG you will see that the VAQ has no additional cooling on the TCR cars which use 265mm Michelin slicks. From twelve years ago there was this quote from the haldex folks:
"The Haldex FXD prototype caused no technical down time and showed no signs of fatigue during the entire 24-hour race. " [Haldex’s new innovative electro hydraulic differential lock, Haldex FXD, debuts in the Volkswagen Scirocco #116 at the 24-hour Nürburgring Race]
If anyone has data to share i'd love to see it
