Champion radiator for ~500hp small block??

Newbomb Turk said
Exactly. Those cookie tray “shrouds” are straight junk.

But the companies sell them so they must work. Not!

I know you know your ****...I respect you

I ran this car with the exact same radiator, fan, engine, sensors, fluids, altitudes, and ambient air temps. No other variables were changed.

I added a shroud and the coolant temps dropped by -15° at idle and -5° at speed.

Please explain how that happened.