Originally Posted by Joey
If backpressure is, as I understand it to be, essentially a clogged airmass in the exhaust stroke of a piston, and it causes the pistons on the opposite crank position to meet with resistance, how does that result in improved fuel economy?
I ask because it would be fairly easy to cut apart my muffler, catalytic converter, and intake box and modify them to be much, much less restrictive, but I know they're not that way from the factory for a reason.
Less low end torque. Back pressure creates torque.
When I removed my cats, it hurt my speed off the line a bit, but made up for it greatly after I got above 40mph or so.