Thumpr camshafts produce a variety of distinctive sounds, including the choppy/thumping idle, rough idle and very rough idle. The models that generate these sounds are the Thumpr, Mutha' Thumpr and Big Mutha' Thumpr, respectively.
The basic Thumpr camshaft fits Ford, Chevrolet and Chrysler street vehicles. It also works on converted stock cars. The Mutha' Thumpr and Big Mutha' Thumpr are suitable for street use and drag racing. In addition to their unique sounds, Thumpr camshafts generate impressive power and torque, according to DragZine. Thumpr camshafts come in hydraulic roller and flat tappet styles. The flat tappet models are particularly easy to install because they do not require any engine adjustments.