I've heard the TCU software is much better in the N55/S55 in terms of power handling and potentially other things, does anyone know what the differences are and/or what would be required to communicate with that TCU software instead?
The software versions are interchangeable, well for the E series at least. I am running 135is (N55) software on my non-is 135i that is also N55 but plenty of people run the same ZB on 335is which is N54 to get the lower Launch Control RPM.
Yep the gearing is significantly different sg vs bg and so the software won’t carry across. 135 and 335 software can because the gearing was the same but not sure about new variants
N54? Not off the top of my head. I'm sure they have failed but perhaps not due to excessive power but rather incorrect tuning, defects or abuse. I think the main reason, is that nobody has pushed one that hard from an N54.
The point being that the work to unlock tuning options for one DCT will likely carry over to the other DCT variants and that large of a market should make it worth doing.
A little birdie told me they have a custom input shaft and gears. So I guess this may not really matter depending on your pay grade.Read a single instance on 2nd gear teeth stripping off on a DCT. They sent the trans to Dodson for them to fix. Maybe doublespaces can get us the low down on it.