heres what nobody gets.. At the first bend and since you have a cat the back pressure is right there.after that nothing matters. . a straight threw muffler is gonna let the exhaust flow out better after that. a muffler with chambers is gonna stop it up more and decrease performance.. i love glasspacks for this reason.
i run 2.5" tube and friends of mine run the same aswell as 3".. this works AWESOME with a header
A fluid dynamics proffessor just chocked and died...
I love this age-old quandry about backpressure...
Truth is, backpressure is no good for an engine, restricts the flow rate of the exhaust and creates an inefficient burn. It is the by-product of backpressure that the engine needs to function properly. This is, of course, heat. Backpressure results in hotter headers/exhaust manifold. The spent exhaust gases leave the combusion chamber under pressure, thus at high speed. They immediatly open up into the head ports and the headers. The mass flow rate hasn't changed, but the greater area of the piping has reduced the velocity of the gas. In order to keep that gas from slowing too much and backing up the entire system, the header tubes must not be too oversized and the header itself must retain heat. Heat = faster exhaust velocity. Best way to build heat in the header...backpressure. It is a carefull balancing act, you want a good flowing exhaust, but if it flows too quickly it will cool the gas too much resulting in, well more backpressure...hehehehe kinda like a catch 22, huh? This is why ceramic coatings and header tapes can be effective...not to keep your engine bay cooler, but to keep your exhaust gasses hotter. K, I'm spent.
