This is not worthy of a separate thread, but here is a recap of my understanding as well an explanation for the difference between the three chips, and how it works with the N57 diesel engine. The observations are based on an email I received from Racechip, my self-study, and feedback from other users here:
• Racechip: "Setting ‘E/2’ is in every RaceChip more or less the same performance level and way not the maximum that can be reached". Deduction: settings in all three chips respond proportionally the same way. Racechip One, must therefore not have the all the same settings. That also explains they minimal power difference between Pro2 and Ultimate which have the same number of settings.
• The only key difference between the three chips is the processor. Race chip: "Actually the difference between the three RaceChip is mainly the processor: The processor can optimize the values as faster is the throttle response and the performance evolvement, the engine runs smooth...". Deduction: the feel of the more pricy chip will be better as it makes for smoother throttle adjustments and responds to engine readings quicker.
• They have "done a lot of tests with especially this N57 block we do have many recommendations concerning different settings.....", with some "...stronger than E/2 but still not causing any error messages." Deduction, we can take it up a few notches, but maximum is probably not advised. Don't buy it for the advertised maximum power increase, but for somewhere between E/2 and max is the general consensus.
• Pretty much like
opasha mentioned earlier, the faster processor produces a smoother power gain. Question however, what is the processing speed for BMW's engine computers? If the car's processors are at or around the "Pro2" level, we could be throwing money away.
paicapo could chime in to say if there is any difference in smoothness of throttle response and rate of acceleration change -smoothness.
• Although everyone says E2 setting is fine, including Racechip, we do have a user that got the Check Engine Light (CEL) at E2:
http://f15.bimmerpost.com/forums/sho...&postcount=100
• We also know that this is a chip, not a tune based on other emails from the manufacturer
42pilot:
http://f15.bimmerpost.com/forums/sho...&postcount=182. In a thread I cannot find now, I recall reading that the believed advantage of Racechip over Burger was that it was a real tune, and not just more fuel.
• We have
skalberti who cautions use based on personal experience, as BMW is able to identify if a car has been tuned/chipped:
http://f15.bimmerpost.com/forums/sho...&postcount=228. Meanwhile I asked about the chips at Service yesterday and one of the advisors said something to the effect of "we all have chips in our cars here", and that he preferred Burger.
• Racechip does not always know the answers despite the claimed tests -there may be trial and error speculation vs. real tests. User
catapaul switched to setting 0/3 (O/3?) as Racechip recommended that for his 40d; at 3500 the engine would choke. He has only a single post in this forum from NOV'14, and no one has replied to him. Unlikely he will chime in, but hopefully he gets a notice about this post and lets us know what happened.
http://f15.bimmerpost.com/forums/sho...&postcount=230 42pilot also reports conflicting and later corrected comments from Racechip (linked earlier).
This is not an easy sell for me as my wife is the primary driver, and I use the car on the weekends to chauffeur the queen and the children around. It has to be fail proof. Meanwhile, BMW has its own chip for the 30d, which one could argue should be a near perfect match for the 35d. Power gain is not as much, and neither the personal tension and attentiveness that may be needed:
http://f15.bimmerpost.com/forums/sho....php?t=1045505 It seems one does not need to buy the whole kit (including brakes) as the chip has a standalone price and part number.
I admit to having no experience on this subject, and limited second and third hand knowledge from my self-education attempt. And, for now, I remain on the side lines. Perhaps if I leased my views would be different.