Yea, and they do take chances but they can get away with running that small amount of oil and lighter oil because of all the other things they do to control the oil. There's also horsepower to be gained by not running too high oil pressures, and whether or not you really need a hi volume pump is also questionable. Will you suck the pan dry if all the oil gets pumped upstairs? The oil could be wrapped around the crank due to windage or stuck in the valley or heads. There are things learned from racing that can be applied to the street; some tricks are best left for the race track due to their increased maintenance for eking out every last bit of horsepower.