Everything is a contributing factor.... We have huge rubber that transfers all that torque back to the motor as well as the increased rotating mass. The increased grip lets us stay WOT longer and get back on throttle sooner... all adding heat. My car is full race so Ill bounce the limiter rather lose the time in the shifts if I'm close to a breaking zone.... that's what really gets it cooking
I have not looked into those radiators. We are however going to change up our cooling once again... so i look into them.