I found alot of good information in this thread, and just wanted to mention that if anyone is interested in a ppkv2 type of kit, I have a feeler out
here. Personally I believe the quickest way to achieve better track temps is keeping the stock radiator and oil cooler, and then adding a large auxiliary radiator. I have had dual oil coolers myself, and ended up downgrading the second oil cooler to make space for a larger aux radiator instead. As others have said, coolant cooling is really the main bottleneck on track. It also makes sense when you compare the total radiator size of the S55 against the N54. Finally it is also somewhat important to keep the AC off.