Originally Posted by NoTempoLimitN54
But the question remains: What's the difference between the N54 in the 335is and a '07-'10 my 335i N54 with the PPK version 2 installed?(AFAIK).
The additional factory cooling mods are probably the only hardware differences. The tunes are prob more "polished" in the 335is & 1M since that's how they come from the factory. While the PPK is a Factory Option, it's still a 335i that has to be retrofitted for those cooling mods.
The 1M also is loaded with the "M" specific features (LSD, the MT trans, M-Dynamic Traction Control
) that the non-M cars cannot be retrofitted for.