Thunderheader exhaust systems are designed exclusively for select Harley Davidson models. Street and race-only applications are available. Each system works to increase engine performance and overall motorcycle sound. Thunderstorm suggests complimentary engine upgrades such as cams for full-exhaust power gains.
As of December 2010, Thunderheader creates performance exhaust systems for Harley Davidson's V-Rod, Dyna, Dressers, Sportster and Softails. Refer to their website for further model information.
Thunderstorm designs their head pipes -- those attached directly to the cylinder combustion ports -- for horsepower gain and balanced torque. Thunderstorm designs the exhaust collector and diffuser shroud for each system to maximise acoustics and reduce back pressure.
Thunderheader's website suggests upgrading the engine with performance parts such as cams, ignition and air cleaner in order to receive maximum gains from their exhaust systems. Each system works on improving overall engine performance in areas of horsepower and torque, while increasing exhaust sound.