Let's all discuss
N63TU related things here.
Easy mods available for N63TU so far:
1. Air filters swap. Either for X5M (14% more flow)- $100 for both oem X5M filters. Direct fit. Or some aftermarket intake - Dinan has a very good one, but expensive.
http://f15.bimmerpost.com/forums/sho...0&postcount=48
http://f15.bimmerpost.com/forums/sho...8&postcount=19
2. Muffler delete mod. Mainly to unleash V8 sound. Also, saves a bit of weight 40lbs. My guess is it does make engine breath a bit better and maybe even gain a couple of hp?
http://f15.bimmerpost.com/forums/sho...5m+air+filters
3. Extra weight savings: swap stock oem battery to lightweight Deka. Saves another 35lbs. I'm driving on it already for 3 months and no issues. However, I am in AZ, so I can't guarantee how it will behave in colder states.
4. Seat removal and swap for a sport Recaro or Momo) or other lightweight brand). Rear seat - about 75lbs saving. Both front seats - about 150lbs saving. Good sport seat like Recaro weighs about 20lbs. So in total you can get about 200lbs savings. Yes, I know only 1% crazy enough will do it, but hey, I've done it. You can always go back easily.
5. Tune. This is biggest mod. Decide for yourself which one to get.
6. Downpipes - another 20-40whp on the table, but we need more info. Don't think anyone have done it yet on 50i on the forum.
7. Spark plugs from X5M or maybe NGK ones that are 1 step colder and need to gap them down to 0.6mm. There is a thread about it by Maverick:
http://f15.bimmerpost.com/forums/sho....php?t=1505161
8. Meth kit. Meth helps with cooling down IATs and boosting octane. For those in AZ where we only have 91 octane - it's a cheapest way to get "100 octane" equivalent and get cooler IATs - that will allow tune to get better ignition timing and possibly better boost. I'll post later my experience, as I'm most probably going to add meth kit soon.
9.
Brake upgrades. Couple options available. Either 4-piston Brembo brakes from previous gen. X5M E70/E71 - they are basically direct plug-n-play or 6-piston F85 X5M (even better option if you can find it for a good price). There is also a MPBK available if you just want new kit. Here's a thread about brembo 4-pot brakes (too many pages, but hopefully you can get enough info to do a DIY if you'll like the looks and decide to do it):
http://f15.bimmerpost.com/forums/sho...ir+filter+swap
10.
Lowering X5. Eibach, H&R (1st gen. was stiff and bumpy, but H&R just recently came up with 2nd gen. of lowering springs). Here's an excellent write up for Eibach:
http://f15.bimmerpost.com/forums/sho...ghlight=eibach
Repair manual/electric schemes etc:
https://www.newtis.info/tisv2/a/en/f...xdrive50i-sav/
OEM BMW Rim/wheel catalog with pics:
http://felgenkatalog.auto-treff.com/
Blackstone oil analysis thread for 50i:
http://f15.bimmerpost.com/forums/sho....php?t=1507693
OBD BMW error codes: see pdf attachment