from damping energy by transferring it outward through the surface area of the profile provided by the cooling fins 42 and external profile analogous to a radiator airflow over the damper housing improves the cooling performance and stabilizes the temperature at a lower level for the duration of a race with the off road vehicle the rate of cooling has been tested and found to reduce peak temperatures by as much as 100 degrees f which constitutes as much as a 33 reduction in temperature steel shock tubes under the same test conditions often reach peak temperatures of 325 degrees f and above fig1 and 12 illustrate the steps in the manufacturing procedure for the radial bypass damper housing 22 an aluminum alloy extrusion process is used the steps of which are conventional for extruding aluminum alloy housings albeit unique as it applied to the damper housing of the invention a tool die is made with the parts cross sectional profile machined in its center the outer features of the damper housing are incorporated in to the tool die the die is placed in a conventional extrusion apparatus and semi molten aluminum alloy is forced through the die at high pressure and cooled upon exit to maintain the shape with minimal distortion over a 12 u2032 length the steps of manufacture are 1 initially solid profile of aluminum alloy is extruded such as in 12 foot lengths 2 the solid profile is cut to desired lengths e g four different lengths 3 the main hole cylinder is located e g 3 inch diameter 4 radial bypass bosses are milled to length 5 the longitudinal auxiliary hole centers are located 6 the longitudinal auxiliary holes are gun drilled 7 the main hole is precision bored and honed to.