[asbrr]

Ok so since I'm the OP, let me add my 2 cents to this conversation.

Of course everyone has their preferences, I could certainly have afforded a 135i of various types (N54, N55 whatever), but I specifically purchased the 128i for the following reasons:

- I like the idea of the 128i being the last "classic formula" BMW. RWD, small/compact, normally aspirated inline 6, manual box, hydraulic steering. To me this is as close to a modern version of my old E36 M3 as I can get. About the same power to weight (bit better once I have my mods done likely), modern build quality, and just "enough" modern conveniences for me.

- It is a daily driver year round for me, and would like to keep the car for 4-5 years. Despite improvements with the N55, the cost of maintenance is going to be higher on the 135 than on this car (I'm not going to get into the list of higher maintenance points here, but my opinion is that it's more on a 135 regardless). As important as power is, it's not the end all be all for me so I'd rather take that money and put it into other mods for the car....and just have less to "worry" about.

- I just like the power delivery and immediacy of a normally aspirated motor. I've had both turbo and NA motors, this is what I prefer. Again, it's not about absolute power, the N52 has more than enough low end torque to get going, if I could change one thing is the top end which the 3 stage manifold will help with, and if I really wanted to a header would help even more with. Even so, not a fan of most modern day turbos with their plateau like torque delivery that falls off after 5krpm (in most cases). This is exacerbated by tunes/chips even further....just not for me.

I just did my first track day at a "larger/high speed" track and sure I could have used some more power on the long back straight, but I was much more concerned with nailing the right braking and turn in points....I'm way beyond caring about who's reeling me in on the straight....never was that way and never will be. EDIT/ADD: Forgot to add that this was not my first track day in the 128i, I did a couple of days at a different/smaller and more technical track, did not feel the lack of power there...so again, for me, the chassis as I have it set up can take a bit more power sure, but it's not taking away from my enjoyment of the car at the moment....

My motivation to tune the engine is not just in search of more power - sure that's nice, it's about getting closer to the power delivery that I like in an NA engine. My old E36 M3 was one of the rare (#25 of 45 imported to Canada) Euro-spec machines with ITBs, and the 280hp 3.0 S50B30EU motor - loved that engine. My immediate previous car to the 128i was an RX-8, revved to 9k rpm...ideally if I could add some of the mojo of those motors to the N52, I'd be perfectly happy with say 250-260 hp if it was delivered in a way closer to those engines (note I said closer, not exactly, that's not a reasonable expectation).

After a week of a simple stage 1 tune, I have to say the car is still surprising me, the power delivery has smoothed out, it's muscular all around, the dead spot in the low end of the throttle is gone....can't complain too much honestly. If the 3 stage IM adds another bunch of power and helps shape the top end a bit, I will be a happy camper. These are the LAST set of mods I've planned to the car, I've been focusing mostly on suspension/chassis style mods first:

- 135i front calipers & rotors, SS Lines all around, B12 kit with Dinan camber plates and RSMs, Whiteline 2 piece RSFBs, AKG DSSR, BMW Perf Shift knob, M-Factory Helical Diff, Rouge Engineering transmission mounts

So power adders have been last on the list, that gives you an idea of my priorities....I don't think I would've done anything different had I bought the 135i (save the brakes, as it would come with the 135 brakes obviously). In fact for a 135i I probably wouldn't modify the engine at all.....