i have a question for the exhaust buffs out there.

I know that too big an exhaust is not so good for a motor. I have been told this is due to a lack of back pressure, which will burnout valves.

Not that i dont believe that, but my logic says that the bigger the better.
I would think that the quicker the exhaust gasses leave the scene of the crime, the more available space for fresh fuel/air mix. This is the reason that you port/polish your head and match to the headers.
At the drags lots of folk remove the exhaust altogether and my bros super-mod just runs headers with hotdogs and no equalizer pipe which you aparently need on twin/split exhaust systems.

Can someone please explain exactly what the story is with this so called evil back pressure and buring valves or is this an old wives tale and Whats the equaliser pipe for on split/twin systems?


thanks