Warped discs?

I warped 2 sets of discs when my car had the orginal calipers anh hangers.

Since fitting the 312mm brake set up theres no warping.

This could be down to 2 reasons, the 288mm brakes are not up the job and got too hot, were as the 312mms are more than adequate.

or there was a fault with the calipers or the hangers were bent.