Originally Posted by abhishriv
this may be a stupid question but I'm not too familiar on this topic.. i've been searching on the topic of oil coolers for our cars. my 335i came equipped with the stock oil cooler but I've noticed on hot days i will easily approach ~110-120 degrees C (about 230-250F)... and it got me thinking that if i was to track my car, which i do plan on doing, that it will easily go over that. i know some people have replaced the stock oil cooler with bigger ones but it is possible to use an aftermarket one in CONJUNCTION with the stock one being left in place? or is it just better to replace the stock oil cooler core with a bigger aftermarket one? would love if any one could shed light on this.. also if anyone knows of a DIY for this upgrade
You can do any of both.
Upgrades for the (rather small) stock oil cooler come from Evolution Racewerks for example. IMO that is sufficient as a first step and easier for installation than adding another oil cooler. The latter is also feasible, AR Design for example offer this solution where the second oil cooler is located in front of the radiator.
Like enrita, I'm running both an additional oil cooler and an upgraded stock core. Ideal if you have modified your car heavily and want to do road racing regularly.