Hi Amigo,
I have done track days where thare have been myself and Trelo running Hartge set-ups, and Boo with JCW. We all have the OEM oil temp guage, and are running similar equipment and lapping in similar times.
The JCW kit does not run anywhere near as hot as the Hartge.
In fact, now I have the oil cooler fitted, my car runs similar temps to Boo's without oil cooler, ie maxes out at around 125C.
I have also done track days with GreenDevil, who has amd, but unfortunately he doesn't have an oil temp guage.
I dont know the reason for the difference. Both cars have similar fuel consumption on the track, and run similar water temps.
However, these temp problems are only under extreme track use. There is never a problem with spirited road driving. Whenever I post on this subject, somone allways replies saying they have Hartge etc and don't have problems. I would emphase that this is EXTREME driving conditions, and it would not be possible to drive that hard on the road. On the track fuel consumption averages 30l/100km+ over a 20-30km section without a break, which gives an idea how hard it is running.
Cheers
Robbo