Although the race is broadcast in surround, the "Crank It Up" is just a gimmick to get you to crank up your volume. But yes they probably have a couple of mics picking up the sound.
It sounds pretty good on my Harman Kardon/ Infinity system, but I wish my Dish reciever could put out DD5. 1 or DTS like my HK DVD player and Xbox does. Dish sells a DD5. 1 adapter for my Dish5000 reciever. I might check into one of those.