Anyone who thinks the laws of physics don't apply to a RACE CAR has "no clue how to set up a RACE car".

Regardless of how you define driveline angle, working angle, operating angle or pinion angle, please give me one reason why you don't want the pinion to run directly in line with, or parallel with the transmission when a RACE CAR is UNDER POWER.

Google is also your friend.

Did you even look at the video demonstrations in this thread?