jpark wrote:GFsEscape wrote:Anyone using the word "backpressure" to explain how an exhaust works doesn't really know what they are talking about.
Stop presenting what you think you know as fact.
If it persists I'll be calling out your posts individually.
I don't recall reviewing your application for moderating E-C. Maybe I misplaced it.
BTW, "exhaust back pressure" is a perfectly legitimate phrase.
It is a perfectly legitimate phrase when referring to a plugged cat. Not being a necessity to improving or maintaining torque.
The use of the word backpressure is a blanket term that typically reflects its user's lack of understanding regarding exhaust gas velocity and volume in relation to pipe diameter and how it affects the scavenging effect created by an exhaust-valve generated pulse throughout the exhaust system.
The issue usually at hand is grossly mismatched tuning between intake and exhaust. I'll use an example from this thread: If you cut the exhaust off an F-150 4.3L V6 truck motor you now have an exhaust tuned toward high RPM performance that is fighting every other component in the engine, which were all made for low RPM performance (from the intake tubing, to throttle body, to intake manifold plenum and runners, to ports, to valves, to combustion chamber, to camshaft profile). The effect is you don't get much high-end or low-end power. This is NOT because you don't have enough exhaust back pressure.
THE SOLUTION may be to start changing low-RPM parts into high-RPM parts so that they can compliment each other and "catch up" to the exhaust. OR decide this-defies-the-use-you-want-for-this-vehicle/it will cost too much $ and effort.
I think it will work great for some people. Hopefully he will open up the intake and utilize the the power in the upper RPM's.
