Yeah, You started off saying backpressure is bad then toward the end you say you have to have some backpressure to keep the gasses hot???
if you think hes not making sense and being contradictory by saying backpressure is bad but you need it, think of it this way. if you could somehow keep the heat caused by backpressure and thus keep exhaust gas velocity up, YET HAVE NO BACKPRESSURE, that would be ideal. BUT THAT IS NOT POSSIBLE. Like he said its a balancing act, you NEED backpressure, but the less you can get away with the better.
so in summation, BACKPRESSURE=NOT GOOD, BACKPRESSURE=NECESSARY
