Indeed, my understanding is that pretty much any NA engine needs a littl eback pressure....not sure why though.

 

On a turbocharged engine, the turbo provides a lot of backpressure, since all of the exhaust has to pass through the turbine, thus they can use very free flowing exhaust systems.

for instance in some racing classes, having a turbo counts as a muffler.

 

Interesting. Ya learn something new every day.

 

which is why i started the thread

 

LOL goodtimes!!