Planning on modding, which year 135i is best?

[MikeVictor]

Originally Posted by Trojan4evr

Wrong. The early n54s up to 09 are reported to have stronger internal. 3 335 owners that opened up the their engines have confirmed.

Yup

[Cornhusker]

sweet, good info, looks like you can't beat a 09 for best all around package. Unless you want dct of course.

[Cornhusker]

Originally Posted by sear

OP, I'm @ 6k ft in CO and have a few posts over on the E90 side with dynos' timing of what to expect at elevation. Basically, the stock turbos find their inefficient range much quicker at elevation and this can be clearly seen by the slope of both the TQ and HP curves above ~5k rpm. My guess is that RBs will do better on this front, but the effect vs sea level will likely be similar. The N54 is definately a solid platform for altitude performance. You might need to look into octane increasing options on top of just RBs if you are stuck with the crappy 91oct we have here... Good luck

Yep, I've seen your threads! I had a 335i procede v2, without bolt ons I managed a best of 319whp at 5400 rpm but on a mustang dyno, in Utah. That's why I was thinking 400whp with FBO plus RB's pump. For octane though, I'll run a meth setup to be safe at 400whp and keep the torque a lil low under the curve but keep it high above 5k rpm.