To be fair, and I can't believe I'm even offering any explanation for this viewpoint, Clarence isn't claiming that the variation accounts for the full difference between the engines. As far as I can tell, he's claiming that some engines, when dyno'd, do not produce the full baseline horsepower expected from the N20 240 HP version. So for example:
- Engine rolls off the assembly line and dynos 228 HP (5% lower than expected)
- This fails to meet the benchmark, and the engine is then "binned" as a 180 HP version
This is where things get janky. We must assume at this point that the engine will circle back in to some stage of the production where it is re-flashed with the 180 HP ECU package and re-run on the dyno, because we can't simply sell the 180 HP version with "just under" the output of the 240 HP version. That isn't supported by user submitted dyno evidence either.
In order for the scenario described above to make any sense at all, the following conditions must be true:
- BMW's engine manufacturing has a high defect rate
- Producing, dyno testing, reflashing, and dyno testing again is less expensive than simply engineering two versions of the engine
I find both of these claims dubious at best.
So it's either all this bullshit, or BMW simply engineered the two engines accordingly and we haven't discovered exactly what component it is that they changed yet.
Which is more probable?