03-02-2015, 03:24 AM
Hedge, I could be wrong, but I believe the smoother the bend the better the air flows. hand bent pipes use smoother radii to flow better. Whereas machine bent pipes use a more squared off bend, therefore less flow. At least that is what I have been told.
I could have that backwards according to this I found in google searching
Mandrel Bent Versus Crush Bent Piping
Another way to upgrade the exhaust piping from the catalytic converter back to the muffler is to have the exhaust piping mandrel (heat) bent instead of the conventional crush bending. As the name suggests, mandrel bends are achieved through the heating of the piping before bending whereas crush bent just literally mean that the piping is bent entirely by force. However, the main difference between mandrel bent and crush bent piping is the ease of flow. Mandrel piping keeps the pipe at a constant cross-sectional area throughout a bend which makes exhaust flow easier. On the other hand, crush bending deforms the pipe at the bend(s), which can restrict the exhaust flow. The disadvantage of mandrel bending is that it is relatively expensive, because of the costs involved in operating a mandrel bending heat machine.
I could find no reference on "hand bent" ..just Mandrel, crush and CNC
I could have that backwards according to this I found in google searching
Mandrel Bent Versus Crush Bent Piping
Another way to upgrade the exhaust piping from the catalytic converter back to the muffler is to have the exhaust piping mandrel (heat) bent instead of the conventional crush bending. As the name suggests, mandrel bends are achieved through the heating of the piping before bending whereas crush bent just literally mean that the piping is bent entirely by force. However, the main difference between mandrel bent and crush bent piping is the ease of flow. Mandrel piping keeps the pipe at a constant cross-sectional area throughout a bend which makes exhaust flow easier. On the other hand, crush bending deforms the pipe at the bend(s), which can restrict the exhaust flow. The disadvantage of mandrel bending is that it is relatively expensive, because of the costs involved in operating a mandrel bending heat machine.
I could find no reference on "hand bent" ..just Mandrel, crush and CNC