I thought I would post an update on the M24 oil cooler. I just got back from a 2 day event at Road America and I have now a two track comparison under similar conditions (temps) between pre and post oil cooler install.
First to clarify. I had posted earlier that I wasn't sure the M24 oil cooler provided a meaningful difference in max. oil temps, at least based on the stock oil temp gauge. I made a classic apples and oranges mistake of not comparing the performance under the same conditions. I ran my car at Barber after the oil cooler install and said I did not notice any diff in the max oil temp (running the mark between 210F and 300F) but that the oil temp "recovery" on cool down was much faster. I've been to Barber three times since the install and the issue is that oil temps at Barber are just hotter. The track is small, there is a fair amount of elevation change, speeds are lower and there is a lot of up and down speed changes, consequently the motor runs hotter. I had no stock oil cooler baseline at Barber, who knows maybe I would have gotten a limp mode.
I've been now to Road America twice (once pre and once post) and at least a half dozen times to VIR. At both VIR and Road America I can no longer get the oil temp to the mark between 210 and 300F, which was a regular occurrence previously. At Road America (it's always cooler there as the usual summer temps are in the mid 70sF as it was this past Monday and Tues (Badger Audi Club, Road America event) the oil temp would get up to the mid-point between 210 and the next mark up (the middle one between 210 &300).. At VIR even when the temps are in the mid 90s the needle still stays below that same mark. So, overall the M24 oil cooler is effective with lower oil temps on the stock BMW temp gauge as well as quicker recovery to stock temps on the cool down lap. In addition the oil cooling fins are easier to keep clean from bugs and debris given the design is a little bit more open that the stock oil cooler.
Overall, very satisfied with the performance of the oil cooler on the track (probably not a useful upgrade for street only use). Price as most of you know is expensive, but as they say, "pay for quality and only cry once."