All stock intake and exhaust pipes on the Probes are press bent. Although cheaper, this method will cause a bottleneck in the exhaust system due the adjusted overall diameter. Mandrel bent pipes keep their overall diameter throughout the pipe, even through the actual bend. This is more expensive, but keeps the exhaust gases flowing smoothly.

In this table, you can see the differences in the diameter

area between press bent pipes and mandrel bent pipes.

 2-1/2" mandrel bent pipes can gain as much as 1 square

inch over press bending.

This diagram shows the overall differences between mandrel

and press bending. The White pipe on the right is a drawing

of a pipe with a 90º mandrel bend. Notice the bend stays at

a consistent width. The pipe on the right has a 90º press

bend. Notice the restriction in the bend. The drawing on the

top shows the relative difference of the pipe's diameter

at the bends (gray arrows).