that radiator should be exhausting air not blowing it in to the case. Other than that you're case/setup shouldnt have anything to do with it. Make sure you have EVGA Precision and set up the fan control so that you have a linear speed increase from about 50% @ 30 degrees to 100% at 85 degrees. Also, you're card should clock down to about 400Mhz then down to about 50Mhz when it's idle. Note that the card will not clock down and will stay in its P0 power state when you have multiple monitors connected and active. If you ever want it to get nice and cool, use Win+P (on windows) to enable/disable multiple monitors.
When idle, my 570 hovers between 36 and 40 degrees, when playing crysis 2 it gets up to 58, when playing BF3 it gets to 65