Quote:
Originally Posted by ///M1
1. The overall character of the car changed adversely, it was no longer the magical M car that is was, but felt like a 'chipped' 135i (very unlinear with huge spikes of TQ - my dyno charts confirmed the same 'butt dyno' feel, and actually if you look at the graph posted on their website, you see the shape of the TQ curve - very non-linear down low with noticeable burst/spikes followed by drops of TQ - my actual TQ dyno curve literally looked like a seesaw - up down/up down, and of course that translated in what you actually felt).
2. Perhaps on the heels of the above as it relates to character of the car: Turbo lag was more noticeable/pronounced and definitely increased. Not only did I feel power came with a delay, it came very virulently and abruptly. Perhaps to the liking of many, but what was almost a NA aspirated feel of the car was gone, and you got the all or nothing sensation of a turbo car. To me, the biggest difference in the power delivery between the 1///M and 135i was the smoothness and linearity that the M engineers managed to achieve in all those hours of work on the 1M tune, running the aftermarket maps seemed to blow off the M magic dust.
3. Power gains were meager (10whp delta on the dyno and that under the 93 Octane maps, though in their defense they do claim 4% peak on their website, so if anything, it backs their assertions). Considering I gained as much from a silly mid pipe, I expected more from a tune on a FI car.
4. Boost was way too high for completely stock setup (19+ psi on the 93 Octane maps, confirmed with both a boost gauge physically reading actual levels, as well as the AP through the ECU, which of course is way too inefficient for stock turbos and an otherwise stock car, and also very aggressive for stock internals)
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Thanks for your detailed response regarding the Cobb tune. I must say this disappoints me, but I am not all that surprised to be honest. I hope I am wrong as I say this but I think we are going to have to choose from either a linear/NA like power delivery with meager HP increase or a typical turbo like power delivery with typical N54 power delivery. When I spoke with Cobb they informed me that they had two maps, a linear and aggressive maps.
That said I will likely still try their product as I am local to their shop and it just seems like a good fit. I will probably go to their monthly meet to see if anyone with an N54 shows up. Though I anxiously await hearing about whatever tuner you chose to go with at this point.