As a 2014 M135i owner that hve the car mostly for the track days, I also was very concerned about this oil starvation issue. I already sourced the parts for an oil pan/pump upgrade, however, before putting a good amount of bucks into it, I first decided to log the oil pressures on the track to see, for the tires I use and for my driving, how bad this starvation would or wouldn't be.
Nowaday, with MHD, it is very easy to make a good log and yes, at least for my particular model, it does log the oil pressure, I believe directly from the OEM sensor, which lives near the oil filter housing. Along with my GoPro, that has GPS, I managed to put together a video of a couple of very hot laps in a very hot day (35°C).
To put in context the numbers of the video below, a brief description of the cars setup:
- Tune: MHD stage 0 map w/ Catless 3" DP and OEM IC
- Fuel: 98RON E25 (Brazilian premium gas)
- Wheels/Tires: Chinese 18"x8,5"xET35 with KUMHO ECSTA PS71 245/40r18 all around
- Suspension: F80 LCA/TCA
So, as you can see in the video, pressure never drops below 3 bar, and the most critical pressure drop happens when turning left and braking. Anyways, by looking at the charts in MMR website:
https://mmrshop.co.uk/products/bmw-n55-oil-sump-baffle
My understanding is that my engine should be OK, and that corroborates what I got somewhere in this forum, where it was stated that "as long as you are on street tires the OEM sump and oil pump should be enough).
If anyone thinks differently, please let me know, as I still have access to the S55 parts, and I'll buy them as long as they are REALLY necessary to keep my engine alive. For now, by looking at the other data in the video, my conclusion is that, despite the catless DP and the MHD tune with lower coolant targets, engine still runs too hot. IAT goes almost to 80°C at some points, and then the most imediate upgrade is a bigger IC, which I already ordered. If that doeswn't do the trick, then I'll choose between secondary oil cooler or bigger radiator.