Quote:
Originally Posted by KoenG
I'am only stating that when you have the 75, it's not an isolated issue and it's mechanical from nature. Especially with a JB4 which ups the torque, chances are real you run into this kind of behaviour during 1st to 2nd shifts in LC.
I can also imagine that 76 transmissions can have (other?) failure modes that have negative effect on the launch. And of course, there might indeed be a counter on the number of LCs. Although, IMHO, that feels a bit like a scam from BMW.
It's difficult to diagnose that the root cause of a reduced LC function is the same for both cars here.
|
Ah, I understand your point now.
To the the broader audience of skeptics, let's be clear here: I'm not citing opinion or speculation--this happens. One thing I cannot argue is whether or not the launch counter kicks in in the same way with stock cars--none of mine remain stock long enough to tell. That said:
1. I've hit it on 3 cars (2 x F90s and my current M8C)
2. It was objectively diagnosed on my first F90 by the local NW USA BMW Tech through BMW Bellevue with no mention of the "tune"
--- specifically, after 100 launches, the transmission disables ZF's QS3 shift pattern (quick shift) permitting only QS1 and QS2 thereafter across the transmission's entire remaining lifetime. The former is used in Comfort with WOT or increased power-demand; the latter when in sportier modes at the peak of the power band and|or RPM and|or torque (QS3 is reserved for launches). In QS2, tuned or otherwise, you'll occasionally feel the car suppress power during a shift (emphasized mostly from 4th to 5th)
3. I retroactively counted launches (or approximated as best I could thru Dragy records which were a close 1:1 of my launches, i.e. I timed almost all of them). I concluded something like 88--I don't recall the specifics. Given that I know 100 is the limit and I've experienced the loss of QS3 across 3 cars and obviously well over 300 launches, I can tell the difference with my eyes closed or even outside the car from the sound alone. I still launch my M8 today on a weekly basis. Compounded by the validation from BMW NA==this is a thing.