Before he got sick we were working on a car of mine one time and the exhaust was off, he said it is absolutely compulsory to start the motor with no exhaust, just headers.
I didn't argue with him at all and eagerly started it up, the excited cheeky smile he got staring at the motor while your ears bleed.
When ever I take a exhaust off a car or a bike I start the engine, give it a rev or two and think him.