The two tuned pipes shown in the photo are similar, but they are used on different hull types. The chamber painted black is used on a rigger & the un-painted chamber is used on a cat. Both are used for oval racing. Their major diameters are the same, but the tuned length of the unpainted chamber is longer. This longer tuned length is because of the smaller included angle of the baffle cone used on the un-painted chamber. Also the unpainted chamber has no straight flex section & a much shorter flanged header section. Both chambers have a total internal volume that is approximately 24 times the displacement of the engine. A very important fact that allows the use of a long, small ID stinger for the maximum boost amount possible!
Edited by Jim Allen, 04 February 2018 - 08:28 AM.