exhaust system

[Sen Sen]

true dual.
there was no room on mine for it.
so I'm stuck with a single.

[BlazerLT]

Ah, ok, true duals is not recommended for a 4,3L anyways.

[Sen Sen]

just curious..
why not?

[Prince_Chowmein]

Originally Posted by chris15706

So they measure the flow with water? Just wondering what the 28" of water was all about.

No, the "Inches of Water" is simply a measurement of pressure per unit area like PSI.

28 Inches of Water is about 1 PSI gauge.

Their graphic is pressure of air into the muffler (in Inches of Water), versus volume out (i.e., CFM).

They probably chose those units of measurement so that the resultant units of flow out (CFM) made for a nice graphic plot. Also, I wouldn't be surprised if the actual pressure into most mufflers is 1-5 PSI. Above that would probably rip most mufflers apart.

Also, the higher above that index of 1 PSI of exhaust pressure into the muffler, one would expect a higher differential (in terms of back-pressure) between the less restrictive muffler and the more restrictive one, although there is obviously a point of diminishing returns and tuning/optimization (balancing backpressure versus how well the engine breathes) required.

[BlazerLT]

Originally Posted by Prince_Chowmein

No, the "Inches of Water" is simply a measurement of pressure per unit area like PSI.

28 Inches of Water is about 1 PSI gauge.

Their graphic is pressure of air into the muffler (in Inches of Water), versus volume out (i.e., CFM).

They probably chose those units of measurement so that the resultant units of flow out (CFM) made for a nice graphic plot. Also, I wouldn't be surprised if the actual pressure into most mufflers is 1-5 PSI. Above that would probably rip most mufflers apart.

Also, the higher above that index of 1 PSI of exhaust pressure into the muffler, one would expect a higher differential (in terms of back-pressure) between the less restrictive muffler and the more restrictive one, although there is obviously a point of diminishing returns and tuning/optimization (balancing backpressure versus how well the engine breathes) required.

This is not a marketing ploy. Flowmaster is known for not flowing very well.